Solid state forms of racemic ilaprazole

ABSTRACT

The invention relates to crystalline forms of racemic ilaprazole, 2[[(4-methoxy-3-methyl-2-pyridinyl)-methyl]sulfinyl]-5-(1H-pyrrol-1-yl)1H-Benzimidazole. The invention also relates to a pharmaceutical composition for inhibiting gastric acid secretion comprising a crystalline Form of ilaprazole according to the invention in an amount effective to inhibit gastric acid secretion and a pharmaceutically acceptable carrier. The invention also provides methods of treatment for various acid-related gastrointestinal (GI) disorders.

PRIORITY STATEMENT

This application is a divisional of U.S. application Ser. No.11/966,868, filed Dec. 28, 2007, now a U.S. Pat. No. 7,999,110, whichclaims benefit under 35 U.S.C. §119(e) of U.S. Provisional ApplicationNo. 60/877,608, filed Dec. 29, 2006 and U.S. Provisional Application No.60/887,499, filed Jan. 31, 2007, all of which are herein incorporated byreference in their entirety.

FIELD OF THE INVENTION

This invention relates to ilaprazole,2[[(4-methoxy-3-methyl-2-pyridinyl)-methyl]sulfinyl]-5-(1H-pyrrol-1-yl)1H-Benzimidazole, a substituted benzimidazole having a chiral sulfuratom. More particularly, the invention relates to solid state forms ofracemic ilaprazole. Ilaprazole is a proton pump inhibitor and is usefulin the treatment of various acid-related gastrointestinal disorders.

BACKGROUND OF THE INVENTION

Since their introduction in the late 1980s, proton pump inhibitors haveimproved the treatment of various acid-related gastrointestinal (GI)disorders, including gastroesophageal reflux disease (GERD), pepticulcer disease, Zollinger-Ellison Syndrome (ZES), ulcers, andnonsteroidal anti-inflammatory drug (NSAID)-induced gastropathy. GERDencompasses three disease categories: non-erosive reflux disease (NERD),erosive esophagitis, and Barrett's esophagus. ZES is caused by agastrin-secreting tumor of the pancreas that stimulates theacid-secreting cells of the stomach to maximal activity. Proton pumpinhibitors have also be used to treat ulcers such as duodenal, gastric,and NSAID-associated gastric/duodenal ulcers.

As antisecretory drugs, proton pump inhibitors are currently therecommended first line therapy, being viewed as more effective thanother treatments. In general, proton pump inhibitors offer superiorgastric acid suppression over histamine H2-receptor blockers. The use ofproton pump inhibitors by patients who suffer from gastric acid-relateddisorders is generally believed to have led to an increase in theirquality of life, productivity, and overall well being.

Proton pump inhibitors are also used to treat extra-esophagealmanifestations of GERD (asthma, hoarseness, chronic cough, non-cardiacchest pain), and with antibiotics for Helicobacter pylori eradication.The goals of GERD management are threefold: prompt and sustained symptomcontrol, healing of the injured esophageal mucosa and prevention ofGERD-related complications (including stricture Formation, Barrett'sesophagus, and/or adenocarcinoma). Pharmacological therapy with protonpump inhibitors Forms the basis of both acute and long-term managementof GERD. Proton pump inhibitors provide effective relief of symptoms andhealing of the esophagitis, as well as sustaining long-term remission.

Although therapeutic efficacy is the primary concern for a therapeuticagent, the solid-state form, as well as the salt form, and theproperties unique to the particular form of a drug candidate are oftenequally important to its development. Each solid state form (crystallineor amorphous) of a drug candidate can have different physical andchemical properties, for example, solubility, stability, or the abilityto be reproduced. These properties can impact the ultimatepharmaceutical dosage form, the optimization of manufacturing processes,and absorption in the body. Moreover, finding the most adequate form forfurther drug development can reduce the term and the cost of thatdevelopment.

Obtaining substantially pure crystalline, amorphous or even othernon-crystalline forms is extremely useful in drug development. Itpermits better characterization of the drug candidate's chemical andphysical properties and thereby allows identification of the form orforms with the desired combination of therapeutic effect and comparativeease of manufacture. The solid state crystalline form may possess morefavorable pharmacology than the amorphous form or may be easier toprocess. It may also possess more storage stability.

The solid state physical properties of a drug candidate may alsoinfluence its selection as a pharmaceutical active ingredient and thechoice of form for its pharmaceutical composition. One such physicalproperty, for example, is the flowability of the solid, before and aftermilling. Flowability affects the ease with which the material is handledduring processing into a pharmaceutical composition. When particles ofthe powdered compound do not flow past each other easily, a formulationspecialist must take that fact into account in developing a tablet orcapsule formulation, which may necessitate the use of glidants such ascolloidal silicon dioxide, talc, starch or tribasic calcium phosphate.Another important solid state property of a pharmaceutical compound isits dissolution rate in aqueous fluid. The rate of dissolution of anactive ingredient in a patient's gastrointestinal fluid may havetherapeutic consequences since it impacts the rate at which anorally-administered active ingredient may reach the patient'sbloodstream.

These practical physical properties are influenced by the properties ofthe particular solid state form of the compound, for example, by theconformation and orientation of molecules in the unit cell of thecrystalline compound. A crystalline form often has different thermalbehavior characteristics from an amorphous, a non-crystalline form oranother polymorphic form. Thermal behavior is measured in the laboratoryby such techniques as capillary melting point, thermogravimetricanalysis (TGA) and differential scanning calorimetry (DSC) and may beused, for example, to distinguish some polymorphic forms from others. Aparticular solid state form generally possesses distinctcrystallographic and spectroscopic properties detectable by powder X-raydiffraction (XRPD), single crystal X-ray crystallography, solid stateNMR, and infrared spectrometry among other techniques.

SUMMARY OF THE INVENTION

The invention relates to solid state forms of racemic ilaprazole,2[[(4-methoxy-3-methyl-2-pyridinyl)-methyl]sulfinyl]-5-(1H-pyrrol-1-yl)1H-Benzimidazole. The invention also relates to a pharmaceuticalcomposition for inhibiting gastric acid secretion comprising acrystalline form of racemic ilaprazole according to the invention in anamount effective to inhibit gastric acid secretion and apharmaceutically acceptable carrier. The invention also provides methodsof treatment for various acid-related gastrointestinal (GI) disorderssuch as those discussed above.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a comparison of the XRPD patterns of the crystalline forms ofracemic ilaprazole.

FIG. 2 is a comparison of the solid state ¹³C CP/MAS NMR spectra ofcrystalline Forms A, B, E, and F of racemic ilaprazole.

FIG. 3 is a comparison of the IR spectra of the crystalline forms ofracemic ilaprazole.

FIG. 4 is a comparison of the Raman spectra of crystalline Forms A, B,and I of racemic ilaprazole.

FIG. 5 is the XRPD pattern of racemic ilaprazole, Form A.

FIG. 6 is the TGA thermogram of racemic ilaprazole, Form A.

FIG. 7 is the DSC thermogram of racemic ilaprazole, Form A.

FIG. 8 is the proton NMR spectrum of racemic ilaprazole, Form A.

FIG. 9 is the solid state ¹³C CP/MAS ssNMR spectrum of racemicilaprazole, Form A.

FIG. 10 is the IR spectrum of racemic ilaprazole, Form A.

FIG. 11 is the RAMAN spectrum of racemic ilaprazole, Form A.

FIG. 12 is the DVS isotherm of racemic ilaprazole, Form A.

FIG. 13 is an ORTEP drawing of racemic ilaprazole Form A. Atoms arerepresented by 50% probability anisotropic thermal ellipsoids

FIG. 14 is the packing diagram of racemic ilaprazole Form A viewed downthe crystallographic a axis.

FIG. 15 is the packing diagram of racemic ilaprazole Form A viewed downthe crystallographic b axis.

FIG. 16 is the packing diagram of racemic ilaprazole Form A viewed downthe crystallographic c axis.

FIG. 17 is the calculated X-ray powder pattern of racemic ilaprazoleForm A based on the single crystal X-ray data.

FIG. 18 is a comparison of the calculated XRPD pattern of racemicilaprazole Form A to the experimental XRPD of racemic ilaprazole Form A.

FIG. 19 is the XRPD pattern of racemic ilaprazole, Form F.

FIG. 20 is the TGA thermogram of racemic ilaprazole, Form F.

FIG. 21 is the DSC thermogram of racemic ilaprazole, Form F.

FIG. 22 is the proton NMR spectrum of racemic ilaprazole, Form F.

FIG. 23 is the solid state ¹³C CP/MAS ssNMR spectrum of racemicilaprazole, Form F.

FIG. 24 is the IR spectrum of racemic ilaprazole, Form F.

FIG. 25 is the RAMAN spectrum of racemic ilaprazole, Form F.

FIG. 26 is the DVS isotherm of racemic ilaprazole, Form F.

FIG. 27 ORTEP drawing of racemic ilaprazole Form F. Atoms arerepresented by 50% probability anisotropic thermal ellipsoids

FIG. 28 is the packing diagram of racemic ilaprazole Form F viewed downthe crystallographic a axis.

FIG. 29 is the packing diagram of racemic ilaprazole Form F viewed downthe crystallographic b axis.

FIG. 30 is the packing diagram of racemic ilaprazole Form F viewed downthe crystallographic c axis.

FIG. 31 Comparison of the packing along the crystallographic b axis forracemic ilaprazole Form F (top) and Form A (bottom). The layers arehighlighted by arrows show the alternating arrangement of the layers forthe Form F crystal structure.

FIG. 32 is the calculated X-ray powder pattern of racemic ilaprazole,Form F.

FIG. 33 is a comparison of the calculated XRPD of racemic ilaprazole,Form F (top) with the experimental XRPD of racemic ilaprazole, Form F(bottom).

FIG. 34 is the XRPD pattern of racemic ilaprazole, Form I.

FIG. 35 is the TGA thermogram of racemic ilaprazole, Form I.

FIG. 36 is the DSC thermogram of racemic ilaprazole, Form I.

FIG. 37 is the proton NMR spectrum of racemic ilaprazole, Form I.

FIG. 38 is the IR spectrum of racemic ilaprazole, Form I.

FIG. 39 is the RAMAN spectrum of racemic ilaprazole, Form I.

FIG. 40 is the DVS isotherm of racemic ilaprazole, Form I.

FIG. 41 is the XRPD pattern of racemic ilaprazole, Form B.

FIG. 42 is the TGA thermogram of racemic ilaprazole, Form B.

FIG. 43 is the DSC thermogram of racemic ilaprazole, Form B.

FIG. 44 is the proton NMR spectrum of racemic ilaprazole, Form B.

FIG. 45 is the solid state ¹³C CP/MAS ssNMR spectrum of ilaprazole, FormB.

FIG. 46 is the IR spectrum of racemic ilaprazole, Form B.

FIG. 47 is the RAMAN spectrum of racemic ilaprazole, Form B.

FIG. 48 is the DVS isotherm of racemic ilaprazole, Form B.

FIG. 49 is the XRPD pattern of racemic ilaprazole, Form E.

FIG. 50 is the TGA thermogram of racemic ilaprazole, Form E.

FIG. 51 is the DSC thermogram of racemic ilaprazole, Form E.

FIG. 52 is the proton NMR spectrum of racemic ilaprazole, Form E.

FIG. 53 is the solid state ¹³C CP/MAS ssNMR spectrum of racemicilaprazole, Form E.

FIG. 54 is the IR spectrum of racemic ilaprazole, Form E.

FIG. 55 depicts the tableting process for preparing a delayed releasepharmaceutical composition of the invention.

FIG. 56 shows mean plasma concentration versus time profiles of racemicilaprazole following administration of a single 40 mg oral dose ofilaprazole as delayed-release tablets containing Forms A, B or F.

FIG. 57 shows the ¹³C CP/MAS ssNMR spectra of delayed-releaseformulations containing 40 mg of racemic ilaprazole, Forms A, B, and F.

DETAILED DESCRIPTION OF THE INVENTION

Ilaprazole,2[[(4-methoxy-3-methyl-2-pyridinyl)-methyl]sulfinyl]-5-(1H-pyrrol-1-yl)1H-Benzimidazole, is a substituted benzimidazole that acts as a protonpump inhibitor. Ilaprazole selectively and irreversibly inhibits gastricacid secretion through inhibition of the hydrogen-potassium adenosinetriphosphatase (H+K+-ATPase) (proton pump) mechanism. Inhibition of theproton pump occurs by formation of disulfide covalent bonds withaccessible cysteines on the enzyme. Ilaprazole has a prolonged durationof action that persists after their elimination from plasma. See, forexample, U.S. Pat. Nos. 5,703,097 and 6,280,773, which are incorporatedherein by reference.

Ilaprazole has the empirical formula C₁₉H₁₈N₄O₂S having a molecularweight of 366.44 daltons. Ilaprazole is a chiral molecule and has thefollowing structural Formula (I):

Ilaprazole, like all proton pump inhibitors, possesses the uniquefeature of a chiral sulfur atom, S*. This can be depicted as followswith the lone pair of electrons on the chiral sulfur atom occupying oneposition in each stereoisomer, as shown below:

The absolute structure and absolute confirmation of (−)-S-ilaprazole wasmade through single crystal structure determination and is shown below.See Example 7 of co-pending U.S. application Ser. No. 11/966,808 ofBrackett et al. entitled, “Solid State Forms of Enantiopure Ilaprazole”filed Dec. 28, 2007, herein incorporated by reference in its entirety.

Thus, its complimentary enantiomer is (+)-R-ilaprazole, as shown below.

Chiral molecules are well known to chemists. Chiral molecules exist intwo enantiomorphic forms that are mirror images of each other. In thesame manner that left and right hands are mirror images of each otherand cannot be superimposed over each other, enantiomers of chiralmolecules cannot be superimposed over each other. The only difference inthe molecules is the arrangement of groups connected to the chiralcenter in three dimensional space. The physical properties ofenantiomers are identical to each other with the exception of therotation of the plane of polarized light. It is this rotation ofpolarized light that allows one skilled in the art to determine if achiral material is enantiomerically pure.

In the solid state, pure enantiomeric materials (also known asenantiopure materials) are, by definition, composed of a singleenantiomer and can have very different properties compared to racemates.This is particularly true in the crystalline form. Racemates cancrystallize as a conglomerate (where the two enantiomers form identical,mirror-image crystals that are the pure enantiomer), a racemic compound(where the two enantiomers coexist and are incorporated into specificlocations of the crystal) or a solid solution (where the enantiomers canbe located at random sites within the crystal). The solid state can becharacterized by various physical properties such as solubility, meltingpoint, x-ray powder diffraction, solid state NMR, Raman, and IRspectroscopy.

The solid state forms of racemic ilaprazole of the invention aredesignated as Forms A, B, E, F, and I. Each crystalline form of racemicilaprazole of the invention is described in the Examples below. FIGS.1-4 are comparison figures showing the XRPD patterns, the solid state¹³C CP/MAS NMR spectra, the IR spectra, and the Raman spectra of thecrystalline forms of racemic ilaprazole according to the invention. Thedifferent crystalline forms of racemic ilaprazole can be identified orcharacterized by comparing their respective spectra. Similarities mayalso be seen, such as the common XRPD peak at 15.8°2θ±0.2°2θ. The protonNMR spectra are useful in showing that each ilaprazole form ischemically the same as the starting material. Additional data for eachcrystalline form which may be used to identify each form is presented inthe Examples below. Each form disclosed here possesses advantagesvis-à-vis the other forms, for example, for a particular formulation orprocessing.

The term “racemic” or “racemate,” is defined as a 1:1 mixture of the twoenantiomers of ilaprazole regardless of their physical state. A racemicmixture of ilaprazole can be composed of individual crystals which maybe the pure enantiomers or ratios of the R and S enantiomers, such as90/10, 10/90, 86/14, 14/86, 70/30, 30/70, 50/50, as well as other ratiosin between these ratios, as long as the bulk enantiomeric compositionremains 1:1.

The forms of racemic ilaprazole of the invention are each substantiallypure or substantially free of the other crystalline forms or amorphousracemic ilaprazole and other impurities. In this context, “substantiallypure” means that the particular form of racemic ilaprazole comprisesless than 15% of another crystalline or amorphous form. The purity ispreferably less than 10%, more preferably less than 5%, more preferablyless than 2%, more preferably less than 1%, and even more preferablyless than 0.5%. The term “substantially pure” also means that the formof racemic ilaprazole comprises less than 3% of other impurities,preferably less than 2%, more preferably less than 1%, and even morepreferably less than 0.5%.

Racemic ilaprazole Form A is the most thermodynamically stable of thesecrystalline Forms. Form A is also the least soluble in aqueoussolutions. It is not hygroscopic. A human bioavailability study of FormsA, B, and F, described in Example 9, showed Form A to be also the mostbio-available form in humans. This is a surprising and unexpectedcombination of characteristics which causes racemic ilaprazole Form A tobe a preferred form for solid dosage forms of the invention.

Racemic ilaprazole, Form A crystallizes with the monoclinic space groupP2₁, which is not centrosymmetric (i.e. does not contain a center ofsymmetry). Surprisingly, unequal numbers of R and S isomers can coexistwithin this structure. Three Form A single crystal structures weredetermined. While not wishing to be bound by theory, it believed that anindividual crystal of Form A contains an approximate 70/30 (or 30/70)mixture of the R and S isomers. The arrangement of isomers appearsdisordered and is manifest in the crystallographic data as two atomicpositions for the single oxygen bound to the chiral sulfur of thesulfoxide group. It is believed that each oxygen position represents oneisomer and is partially occupied (e.g. one position is 70% R(S) occupiedand the other is 30% S(R) occupied).

Structures were determined for both enantiomeric compositions. Two ofthe predicted structures contained enantiomeric ratios of approximately70-30 while another had a ratio of approximately 28-72, suggesting thatsuch a ratio is preferred under these conditions. However, the bulkmaterial is racemic, as demonstrated by a net 0° rotation of planepolarized light, indicating that the bulk material containsapproximately equal numbers of crystals with ratios of 70% R/30% S and30% R/70% S.

Chiral HPLC analysis was performed on a single crystal of Form A forwhich the structure had been determined. The result was consistent withenantiomeric enrichment of one isomer, whereas the analysis of bulkracemic ilaprazole, Form A material was consistent with a 50/50 racemicmixture. When crystallized from racemic solution at ambient temperature,Form A can be characterized as a solid solution in which individualcrystals may contain mixture of the R and S isomers. This behavior issimilar to that described by a conglomerate, except that a conglomerateis composed of equal numbers of pure S and pure R crystals.

Racemic ilaprazole Form F is believed to be a kinetically favoredcrystal form. Under certain conditions, e.g., temperatures, aqueousmixed solvent composition, and pH gradients, Form F is more soluble inaqueous solvents than Form A. Solubility studies are shown in Example 6.Like Form B, Form F is less bioavailable than Form A. It too may be usedto prepare longer acting pharmaceutical compositions. Form F has thelongest half-life of the crystalline Forms A, B, and F which wereevaluated in the bioavailability study of Forms A, B, and F, Example 9.Form F is slightly hygroscopic.

Form F crystallizes with the centrosymmetric space group P2₁/n whichmust contain a center of symmetry. Each crystal must contain an equalnumber of R and S isomers. Thus, Form F is a racemic crystal. Thearrangement of isomers within this structure is disordered. There aretwo oxygen atom positions for the oxygen bound to the chiral sulfur ofthe sulfoxide group, each partially occupied in an 86/14 ratio. At firstglance this seems similar to the Form A structure, but the presence of acenter of symmetry in the space group of the Form F structure dictatesit be racemic. Therefore, individual Form F crystals must contain anequal number of both enantiomers. In the disordered Form F structure,half of the crystallographic sites have an enantiomeric or occupancyratio of approximately 86/14 and other half have the opposite ratio ofapproximately 14/86. Chiral HPLC and optical rotation analysis confirmsthat both the single crystals of Form F and the bulk material areracemic.

Racemic ilaprazole Form B crystallizes in pure form from aproticsolvents such as acetone or dichloromethane/ethyl acetate. This leads toa manufacturing advantage. For example, Form B may be used to purifyilaprazole. Form B is also a stable crystalline form having good longterm stability or shelf life. Form B is more soluble in aqueous solventsthan Form A. The bioavailability study of Forms A, B, and F, discussedin Example 9, showed that Form B has a greater half-life than Form Awhich may be advantageously used to prepare longer acting pharmaceuticalcompositions. Form B is not hygroscopic.

Forms B, E, and I are racemic crystalline forms of ilaprazole whoseindividual crystal structures have not been determined. Although theenantiomeric composition of the individual crystal structure is notknown, chiral HPLC confirms that the bulk composition of each of theseforms is racemic, i.e. contains an equimolar mixture of each enantiomer.As mentioned above, the x-ray powder diffraction (XRPD) patterns thesolid state ¹³C CP/MAS NMR spectra, the IR spectra, and the Ramanspectra obtained on these forms show characteristic peaks which identifyeach form. As shown in the Examples, the physical properties of Forms A,B, F, and I, such as melt onset temperature and moisturesorption/desorption profiles, also differ depending on the particularform.

Pharmaceutical Compositions and Methods

Ilaprazole is useful for inhibiting gastric acid secretion as well asfor providing gastrointestinal cytoprotective effects in mammals,including humans. In a more general sense, ilaprazole may be used forprevention and treatment of gastrointestinal inflammatory diseases inmammals, including e.g. gastritis, gastric ulcer, and duodenal ulcer. Asdiscussed above, such GI disorders include, for example,gastroesophageal reflux disease (GERD), peptic ulcer disease,Zollinger-Ellison Syndrome (ZES), ulcers, and nonsteroidalanti-inflammatory drug (NSAID)-induced gastropathy. Ilaprazole may alsobe used for prevention and treatment of other gastrointestinal disorderswhere cytoprotective and/or gastric antisecretory effect is desirable,e.g. in patients with gastrinomas, in patients with acute uppergastrointestinal bleeding, and in patients with a history of chronic andexcessive alcohol consumption.

The results of Phase 1 clinical studies conducted with ilaprazoleresults suggest that at the doses studied, suppression of gastric acidoccurs over a 24-hour period. In Phase 2 clinical studies conducted withilaprazole, the results indicated that ilaprazole at the doses studiedprovided symptomatic relief for patients with gastric-acid relateddisorders and promoted rapid healing of acid-related gastric andduodenal ulcers.

Accordingly, the invention relates to a pharmaceutical composition forinhibiting gastric acid secretion comprising a crystalline form ofracemic ilaprazole according to the invention in an amount effective toinhibit gastric acid secretion and a pharmaceutically acceptablecarrier. Pharmaceutical compositions are discussed below.

The invention also relates to the treatment of various acid-relatedgastrointestinal (GI) inflammatory diseases and disorders such as thosediscussed above and providing gastrointestinal cytoprotection. Theinvention provides a method for inhibiting gastric acid secretion byadministering to mammals a crystalline form of racemic ilaprazoleaccording to the invention, or a pharmaceutical composition containingit, in an amount sufficient to inhibit gastric acid secretion. Theinvention also provides a method for the treatment of gastrointestinalinflammatory diseases in mammals by administering to mammals acrystalline form of racemic ilaprazole according to the invention, or apharmaceutical composition containing it, in an amount sufficient totreat gastrointestinal inflammatory disease. The invention furtherprovides a method for providing gastrointestinal cytoprotective effectsin mammals by administering to mammals a crystalline form of racemicilaprazole according to the invention, or a pharmaceutical compositioncontaining it, in an amount sufficient to provide gastrointestinalcytoprotective effects.

The invention relates to pharmaceutical compositions comprising atherapeutically effective amount of a crystalline form of racemicilaprazole of the invention and a pharmaceutically acceptable carrier,(also known as a pharmaceutically acceptable excipient). Thepharmaceutical composition may also contain a mixture of crystallineform of racemic ilaprazole. As discussed above, the crystalline forms ofracemic ilaprazole are useful for the treatment of various acid-relatedgastrointestinal (GI) disorders. Pharmaceutical compositions for thetreatment of those diseases and disorders contain a therapeuticallyeffective amount of a crystalline form of racemic ilaprazole of theinvention to inhibit gastric secretion as appropriate for treatment of apatient with the particular disease or disorder.

A “therapeutically effective amount of a crystalline form of racemicilaprazole to inhibit gastric secretion” (discussed here concerning thepharmaceutical compositions) refers to an amount sufficient to inhibitor reduce gastric secretion and thereby to treat, i.e. to reduce theeffects, inhibit or prevent, various acid-related gastrointestinal (GI)disorders and/or provide gastrointestinal cytoprotection. The actualamount required for treatment of any particular patient will depend upona variety of factors including the disorder being treated and itsseverity; the specific pharmaceutical composition employed; the age,body weight, general health, sex and diet of the patient; the mode ofadministration; the time of administration; the route of administration;and the rate of excretion of the crystalline form of racemic ilaprazoleaccording to the invention; the duration of the treatment; any drugsused in combination or coincidental with the specific compound employed;and other such factors well known in the medical arts. These factors arediscussed in Goodman and Gilman's “The Pharmacological Basis ofTherapeutics,” Tenth Edition, A. Gilman, J. Hardman and L. Limbird,eds., McGraw-Hill Press, 155-173 (2001), which is incorporated herein byreference.

The absorption of the crystalline forms of racemic ilaprazole can bealtered depending on when the subject consumes food in relation to whenthe dosage is administered. The rate of absorption can also depend onthe type of diet consumed, particularly if the diet has a highconcentration of fats. These factors, as well as others known to thoseof skill in the art that can affect the absorption of proton pumpinhibitors, can consequently influence the efficacy of the crystallineforms of racemic ilaprazole in inhibiting gastric acid secretion. It hasbeen found that the absorption of the crystalline forms of racemicilaprazole can be delayed and the bioavailability increased whenadministered in the fed state or approximately five minutes before ahigh-fat meal, compared to administration in the fasted state.Administration of the crystalline forms of racemic ilaprazoleapproximately one hour before a high-fat meal produces results similarto that observed during administration in the fasted state. Thesefindings are consistent with similar studies performed with othertableted formulations of proton pump inhibitors.

A pharmaceutical composition of the invention may be any pharmaceuticalform which contains and retains the crystalline form of racemicilaprazole according to the invention. The pharmaceutical compositionmay be, for example, a tablet, capsule, liquid suspension, injectable,topical, or transdermal. A comprehensive disclosure of suitableformulations (including controlled-release formulations, e.g. delayedrelease, sustained/extended release, etc.) may be found in U.S.Published Application No. 2006/013868, herein incorporated by referencein its entirety. For injectables and liquid suspensions, those should beformulated such that the crystalline form of racemic ilaprazole ispresent in the formulated composition.

Depending on the type of pharmaceutical composition, thepharmaceutically acceptable carrier may be chosen from any one or acombination of carriers known in the art. The choice of thepharmaceutically acceptable carrier depends upon the pharmaceutical formand the desired method of administration to be used. For apharmaceutical composition of the invention, that is one having acrystalline form of racemic ilaprazole of the invention, a carriershould be chosen that maintains the crystalline form of racemicilaprazole of the invention. In other words, the carrier should notsubstantially alter the crystalline form of the racemic ilaprazole ofthe invention. Nor should the carrier be otherwise incompatible with acrystalline form of racemic ilaprazole according to the invention, suchas by producing any undesirable biological effect or otherwiseinteracting in a deleterious manner with any other component(s) of thepharmaceutical composition.

The pharmaceutical compositions of the invention are preferablyformulated in unit dosage form for ease of administration and uniformityof dosage. A “unit dosage form” refers to a physically discrete unit oftherapeutic agent appropriate for the patient to be treated. It will beunderstood, however, that the total daily dosage of a crystalline formof racemic ilaprazole of the invention and its pharmaceuticalcompositions according to the invention will be decided by the attendingphysician within the scope of sound medical judgment.

It may be desirable to administer the dosage in a composition where thecrystalline form of racemic ilaprazole is released from the dosage formas a first and a second dose where each of the first and second dosecontain a sufficient amount of the crystalline form of racemicilaprazole to raise plasma levels to a desired concentration. Suitableformulations to achieve this are disclosed in PCT Published ApplicationNo. WO 2006/009602, herein incorporated by reference in its entirety.

Because the crystalline form of racemic ilaprazole of the invention ismore easily maintained during their preparation, solid dosage forms arepreferred for the pharmaceutical composition of the invention. Soliddosage forms for oral administration, which includes capsules, tablets,pills, powders, and granules, are particularly preferred. In such soliddosage forms, the active compound is mixed with at least one inert,pharmaceutically acceptable carrier (also known as a pharmaceuticallyacceptable excipient). The solid dosage form may, for example, includeone or more pharmaceutical carriers/excipients as known in the art,including: a) fillers or extenders such as starches, lactose, lactosemonohydrate, sucrose, glucose, mannitol, sodium citrate, dicalciumphosphate, and silicic acid; b) binders such as, for example,carboxymethylcellulose, microcrystalline cellulose, alginates, gelatin,polyvinylpyrrolidinone, sucrose, and acacia; c) humectants such asglycerol; d) disintegrating agents such as agar, calcium carbonate,potato or tapioca starch, alginic acid, certain silicates, sodium starchglycolate, and sodium carbonate; e) dissolution retarding agents such asparaffin; f) absorption accelerators such as quaternary ammoniumcompounds; g) wetting agents such as, for example, cetyl alcohol andglycerol monostearate; h) absorbents such as kaolin and bentonite clay;i) lubricants such as talc, calcium stearate, magnesium stearate,magnesium hydroxide, solid polyethylene glycols, sodium lauryl sulfate;and j) glidants such as colloidal silicon dioxide. The solid dosageforms may also comprise buffering agents. They may optionally containopacifying agents and can also be of a composition that they release theactive ingredient(s) only, or preferentially, in a certain part of theintestinal tract, and/or optionally in a delayed manner Remington'sPharmaceutical Sciences, Sixteenth Edition, E. W. Martin (MackPublishing Co., Easton, Pa., 1980), herein incorporated by reference inits entirety, discloses various carriers used in formulatingpharmaceutical compositions and known techniques for the preparationthereof. Solid dosage forms of pharmaceutical compositions of theinvention can also be prepared with coatings and shells such as entericcoatings and other coatings well known in the pharmaceutical formulatingart, including formulations and coatings designed to provide forextended release of the active pharmaceutical ingredient (API). Forexample, U.S. Pat. No. 6,605,303, incorporated herein by reference,describes oral extended release formulations for the proton pumpinhibitor omeprazole. Accordingly, the solid dosage form may be anextended or delayed release formulation. An exemplary delayed-releasetablet formulation is described in Example 8, below.

A crystalline form of racemic ilaprazole of the invention can also be ina solid microencapsulated form with one or more carriers as discussedabove. Microencapsulated forms of a crystalline form of racemicilaprazole of the invention may also be used in soft and hard-filledgelatin capsules with carriers such as lactose or milk sugar as well ashigh molecular weight polyethylene glycols and the like.

The invention also provides methods for the treatment of the GIdisorders discussed above. The solid forms of racemic ilaprazole andpharmaceutical compositions containing them may, according to theinvention, be administered using any amount, any form of pharmaceuticalcomposition and any route of administration effective for the treatment.After formulation with an appropriate pharmaceutically acceptablecarrier in a desired dosage, as known by those of skill in the art, thepharmaceutical compositions of this invention can be administered tohumans and other animals orally, rectally, parenterally, intraveneously,intracisternally, intravaginally, intraperitoneally, topically (as bypowders, ointments, or drops), bucally, as an oral or nasal spray, orthe like, depending on the location and severity of the condition beingtreated. As discussed above, when administering a pharmaceuticalcompositions of the invention via one of these routes, thepharmaceutical composition contains racemic ilaprazole in one of thecrystalline forms of the invention. Oral administration using tablets orcapsules is generally preferred.

In certain embodiments, the crystalline forms of racemic ilaprazoleaccording to the invention may be administered at dosage levels of about0.001 mg/kg to about 50 mg/kg, from about 0.01 mg/kg to about 25 mg/kg,or from about 0.1 mg/kg to about 10 mg/kg of subject body weight perday, one or more times a day, to obtain the desired therapeutic effect.It will also be appreciated that dosages smaller than 0.001 mg/kg orgreater than 50 mg/kg (for example 50-100 mg/kg) can be administered toa subject. For extended release formulations, the dosage may range fromabout 5 mg to about 80 mg, preferably ranging from about 10 mg to about50 mg ilaprazole, and more preferably ranging from about 20 mg to about40 mg.

EXAMPLES

Example 1 describes the preparation of ilaprazole. Examples 2-4 describethe preparation and characterization of three crystalline forms ofracemic ilaprazole, Forms A, F and I. These solid state forms werecharacterized by various techniques. Each technique is described below.Example 5 describes solubility studies of racemic ilaprazole Forms A andF. Examples 6 and 7 describe the preparation and characterization of twoadditional crystalline forms of racemic ilaprazole, Forms B and E.Example 8 describes delayed release tablet formulations containingracemic ilaprazole Forms A, B, and F. Example 9 describes a humanbioavailability study with those delayed release tablets.

Differential Scanning Calorimetry (DSC): Analyses were carried out on aTA Instruments differential scanning calorimeter 2920 or Q1000. Theinstrument was calibrated using indium as the reference material. Thesample was placed into an aluminum DSC pan and the weight accuratelyrecorded. The sample cell was equilibrated at 25° C. and heated under anitrogen purge at a rate of 10° C./min or 40° C./min, up to a finaltemperature of 350° C. Specific heating rates and pan configurations areidentified in the comment section above each individual thermogram. Panconfigurations are defined as follows: NC is non-crimped and HSP ishermetically sealed.

Dynamic Vapor Sorption/Desorption (DVS): Data were collected on a VTISGA-100 moisture balance system. For sorption isotherms, a sorptionrange of 5 to 95% relative humidity (RH) and a desorption range of 95 to5% RH in 10% RH increments were used for analysis. The samples were notdried prior to analysis. Equilibrium criteria used for analysis wereless than 0.0100% weight change in 5 minutes with a maximumequilibration time of 3 hours if the weight criterion was not met. Datawere not corrected for the initial moisture content of the samples.

IR Spectroscopy: Infrared spectra were acquired on a Magna-IR 860®Fourier transform infrared (FT-IR) spectrophotometer (Thermo Nicolet)equipped with an Ever-Glo mid/far IR source, an extended range potassiumbromide (KBr) beamsplitter, and a deuterated triglycine sulfate (DTGS)detector. An attenuated total reflectance (ATR) accessory (Thunderdome™,Thermo Spectra-Tech), with a germanium (Ge) crystal was used for dataacquisition. The spectra represent 256 co-added scans collected at aspectral resolution of 4 cm⁻¹. A background data set was acquired with aclean Ge crystal. Log 1/R (R=reflectance) spectra were acquired bytaking a ratio of these two data sets against each other. Wavelengthcalibration was performed using polystyrene.

Solution State ¹H NMR Analyses: Samples were prepared for ¹H NMRspectroscopy as ˜5-50 mg solutions in deuterated methylene chloride,CD₂Cl₂. The spectra were obtained on an INOVA-400 spectrometer. Thespectra were obtained with the acquisition parameters in Table 1.

TABLE 1 ¹H NMR Acquisition Parameters Solvent: CD₂Cl₂, (internalreference at 5.32 ppm) Temperature: Ambient Spin rate: 20 Hz Pulsesequence: s2pu1 Relaxation delay: 5 seconds Pulse width: 8.4 μseconds,(90.0 degree) Acquisition time: 2.5 seconds Spectral width: 6400.0 Hz,(16.008 ppm) Scans: 40 Acquired points: 32000 Data processing: Linebroadening: 0.2 Hz FT size: 131072

Solid State ¹³C CP/MAS NMR Analyses (ssNMR): Samples were prepared forsolid-state NMR spectroscopy by packing them into 4 mm PENCIL typezirconia rotors. The spectra were acquired on an INOVA-400 spectrometerusing ¹H cross-polarization (CP) and magic angle spinning, (MAS). Thespecific acquisition parameters are listed in Table 2, with exceptionsnoted for different examples:

TABLE 2 ¹³C ssNMR Acquisition Parameters Reference: Glycine (externalreference at 176.5 ppm) Temperature: Ambient Pulse sequence: xpolvtlrho1Relaxation delay: 10 seconds Pulse width: 2.2 μseconds, (90.0 degree,76.2 degree for Form E (Example 7)) Acquisition time: 0.030 secondsSpectral width: 44994.4 Hz, (447.517 ppm) Scans: 100 for Forms A and F(Examples 2 and 3); 200 with 2 dummy scans for Form B (Example 6); 400with 2 dummy scans for Form E (Example 7) Acquired points: 27000 ¹HDecoupling 400 MHz SPINAL-64 decoupling Cross Polarization tangentRAMP-CP on C13 Contact Time: 5.0 mseconds Spin rate: 12000 Hz Dataprocessing: Backward linear prediction: 3 points Line broadening: 10.0Hz FT size: 3278

Thermogravimetric Analysis (TGA): Thermogravimetric analyses werecarried out on a TA Instruments 2950 thermogravimetric analyzer. Thecalibration standards were nickel and Alumel™. Each sample was placed inan aluminum sample pan and inserted into the TG furnace. Samples werestarted directly from ambient and then heated under a stream of nitrogenat a heating rate of 10° C./min, up to a final temperature of 350° C.

Raman Spectroscopy: Fourier Transfrom-Raman spectra were acquired on anFT-Raman 960 spectrometer (Thermo Nicolet). This spectrometer uses anexcitation wavelength of 1064 nm. Approximately 0.5 W of Nd:YVO4 laserpower was used to irradiate the sample. The Raman spectra were measuredwith an indium gallium arsenide (InGaAs) detector. The samples wereprepared for analysis by placing the sample into a capillary. A total of256 sample scans were collected from 3600-100 cm⁻¹ at a spectralresolution of 4 cm⁻¹, using Happ-Genzel apodization. Wavelengthcalibration was performed using sulfur and cyclohexane.

X-Ray Powder Diffraction (XRPD): XRPD patterns were obtained using thetwo diffractometers discussed below.

Shimadzu XRD-6000 Diffractometer: Analyses were carried out on aShimadzu XRD-6000 X-ray powder diffractometer using Cu Kα radiation. Theinstrument is equipped with a long fine focus X-ray tube. The tubevoltage and amperage were set at 40 kV and 40 mA, respectively. Thedivergence and scattering slits were set at 1° and the receiving slitwas set at 0.15 mm. Diffracted radiation was detected by a NaIscintillation detector. A theta-two theta continuous scan at 3°/min (0.4sec/0.02° step) from 2.5 to 40°2θ was used. A silicon standard wasanalyzed to check the instrument alignment. Samples were prepared foranalysis by placing them in an aluminum/silicon sample holder.

Inel XRG-3000 Diffractometer: Analyses were also performed on an InelXRG-3000 diffractometer, equipped with a curved position-sensitivedetector with a 2θ range of 120°. Real time data were collected using CuKα radiation starting at approximately 4°2θ at a resolution of 0.03°2θ.The tube voltage and amperage were set to 40 kV and 30 mA, respectively.Samples were run for 5 or 15 minutes. Patterns are displayed from 2.5 to40°2θ to facilitate direct pattern comparisons. Samples were preparedfor analysis by packing them into thin-walled glass capillaries. Eachcapillary was mounted onto a goniometer head that is motorized to permitspinning of the capillary during data acquisition. Instrumentcalibration was performed daily using a silicon reference standard.

XRPD Peak Picking Methods: Any XRPD files generated from an Inelinstrument were converted to Shimadzu .raw file using File Monkeyversion 3.0.4. The Shimadzu .raw file was processed by the ShimadzuXRD-6000 version 4.1 software to automatically find peak positions. The“peak position” means the maximum intensity of a peaked intensityprofile. Parameters used in peak selection are shown with each parameterset of the data. The following processes were used with the ShimadzuXRD-6000 “Basic Process” version 2.6 algorithm: 1) smoothing was done onall patterns; 2) the background was subtracted to find the net, relativeintensity of the peaks; and 3) the Cu K alpha2 (1.5444 Å wavelength)peak was subtracted from the pattern at 50% of the Cu K alpha1 (1.5406Å) peak intensity for all patterns. This method was used when selectingall peaks, except Form E. For Form E, peaks were selected using Match v2.3.6 with default parameters.

Each figure listing XRPD peaks for each Form shows peaks selected by thepeak picking method described above. Tables listing peaks for each Formshows peaks that are visually present in the diffractogram. Peaks whichcharacteristically define the particular form are identified. I/Io isrelative intensity.

Example 1 Preparation of Racemic Ilaprazole, Form A

3% NH₄OH/Acetonitrile (MeCN) (6.00 kg, 15.0 parts) was charged to aflask. After adjusting the temperature to 5° C. (2-8° C.), Ilaprazole(0.400 kg) was charged and the contents were agitated for 1 hour. Theslurry was filtered off and the filter cake rinsed with 3% NH₄OH/MeCN(2×0.400 kg, 2×1.00 part).

The filter cake was charged into the flask, followed by 0.5% NH₄OH/EtOH(0.200 kg, 0.500 part) and concentrated at 20-25° C. under reducedpressure, until distillation stopped. 0.5% NH₄OH/EtOH (1.00 kg, 2.50parts) was charged to the flask, followed by methylene chloride (2.40kg, 6.00 parts). The resulting solution was concentrated at 20-25° C.under reduced pressure to ca. 1.0 L (2.50 volumes). 0.5% NH₄OH/EtOH(1.20 kg, 3.00 parts) was charged and the mixture was concentrated atmaximum 20-25° C. under reduced pressure to ca. 1.2 L (3.00 volumes).0.5% NH₄OH/EtOH (0.200 kg, 0.500 part) was charged and the contents wereadjusted to 5° C. (2-8° C.) and agitated for 45 minutes. The slurry wasfiltered off and rinsed with 0.5% NH₄OH/EtOH (0.200 kg, 0.500 part),EtOH (0.200 kg, 0.500 part) and MTBE (2×0.200 kg, 2×0.500 part). Thefilter cake was pull-dried for 2 hours, and further dried under vacuumat maximum temperature of 53° C. for 92 hours. Yield of racemicilaprazole, Form A: 0.338 kg (85%). Particle size: 206

Example 2 Preparation and Characterization of Racemic Ilaprazole Form A

A saturated solution of ilaprazole in acetone and triethylamine wasfiltered through a nylon filter into a glass vial. The open vial wasthen exposed to hexanes vapor within a closed chamber. The sample wasallowed to equilibrate at ambient temperature and humidity. Thecrystals, recovered by decantation, were found to have a morphology ofclustered needles and plates with birefringence and identified asracemic ilaprazole Form A.

The XRPD pattern of racemic ilaprazole Form A was obtained using aShimadzu XRD-6000 X-ray powder diffractometer, as described above. Themeasurement conditions are reported in Table 3. FIG. 5 shows the XRPDpattern for racemic ilaprazole Form A. Table 4 reports the peaksidentified in the XRPD pattern. In its XRPD racemic ilaprazole Form Amay be characterized by peaks at 8.0°2θ±0.2°2θ; 13.2°2θ±0.2°2θ; and24.1°2θ±0.2°2θ. Another characteristic grouping includes peaks at8.0°2θ±0.2°2θ; 31.6°2θ±0.2°2θ; 32.0°2θ±0.2°2θ; 35.5°2θ±0.2°2θ;36.1°2θ±0.2°2θ; 36.3°2θ±0.2°2θ; 37.8°2θ±0.2°2θ; and 38.9°2θ±0.2°2θ.

TABLE 3 Measurement Conditions for XRPD Pattern of Racemic IlaprazoleForm A. Measurement Condition: X-ray tube target = Cu voltage = 40.0(kV) current = 40.0 (mA) Slits divergence slit = 1.00000 (deg) scatterslit = 1.00000 (deg) receiving slit = 0.15000 (mm) Scanning drive axis =2Theta/Theta scan range = 2.500-40.000 scan mode = Continuous Scan scanspeed = 3.0000 (deg/min) sampling pitch = 0.0200 (deg) preset time =0.40 (sec) Data Process Condition: Smoothing [AUTO] smoothing points =13 B.G. Subtraction [AUTO] sampling points = 13 repeat times = 30 Ka1-a2Separate [MANUAL] Ka1 a2 ratio = 50.0 (%) Peak Search [AUTO]differential points = 13 FWHM threshold = 0.050 (deg) intensitythreshold = 30 (par mil) FWHM ratio (n − 1)/n = 2 System ErrorCorrection: [NO] Precise Peak Correction: [NO]

TABLE 3 Peak Positions of Ilaprazole Form A XRPD Pattern Position Peak(°2θ ± 0.2 No. °2θ) d-spacing Intensity I/I_(o) 1 7.5 11.7 39 5 2 8.011.1 426 51 3 8.5 10.4 354 42 4 9.4 9.4 28 3 5 13.2 6.7 96 12 6 15.4 5.7143 17 7 15.7 5.6 833 100 8 16.0 5.5 74 9 9 16.6 5.3 53 6 10 17.8 5.0159 19 11 18.9 4.7 27 3 12 19.7 4.5 218 26 13 20.0 4.4 592 71 14 20.94.3 631 76 15 21.2 4.2 35 4 16 22.5 3.9 36 4 17 23.0 3.9 43 5 18 23.53.8 659 79 19 24.1 3.7 272 33 20 25.1 3.5 54 6 21 25.6 3.5 34 4 22 25.83.5 41 5 23 26.0 3.4 57 7 24 26.8 3.3 81 10 25 27.4 3.3 35 4 26 27.7 3.289 11 27 28.9 3.1 48 6 28 29.2 3.1 62 7 29 29.6 3.0 93 11 30 30.3 2.9 425 31 31.6 2.8 81 10 32 32.0 2.8 115 14 33 35.5 2.5 52 6 34 35.8 2.5 35 435 36.1 2.5 49 6 36 36.3 2.5 46 6 37 37.8 2.4 44 5 38 38.9 2.3 30 4

FIG. 6 is the TGA thermogram of racemic ilaprazole, Form A. The sampleshowed 0.3% weight loss up to 160° C.

FIG. 7 is the DSC thermogram of racemic ilaprazole, Form A. Theendotherm onset was at 167° C. (max 170° C.).

FIG. 8 is the proton NMR Spectrum of racemic ilaprazole, Form A. Peaksnear 5.32 are due to solvent—not to ilaprazole. Peaks near 1.0 and 2.5are due to triethylamine (TEA), which is used to stabilize ilaprazole insolution, and not to ilaprazole.

FIG. 9 is the solid state ¹³C CP/MAS NMR spectrum of racemic ilaprazole,Form A. The spectrum is externally referenced against glycine at 176.5ppm. The peaks in the solid state ¹³C NMR spectrum are reported in Table5. A minor amount of Form F was observed in the solid state ¹³C NMRspectrum. The peaks associated with Form F are not reported in Table 5,although the peak at 148.4 ppm is coincident between the forms.

TABLE 5 Solid State ¹³C NMR Peaks for Racemic Ilaprazole, Form A. PPMHEIGHT 163.9 89.8 154.6 71.1 148.4 104.2 141.8 94.2 139.1 92.8 137.2105.2 123.9 66.1 122.1 88.6 120.1 141.8 111.6 83.2 108.2 80.9 61.0 63.856.1 135.6 12.6 104.2

FIG. 10 is the IR spectrum of racemic ilaprazole, Form A. Table 6reports the absorbance peaks in the IR spectrum.

TABLE 6 Peaks in IR Spectrum of Racemic Ilaprazole, Form A Position:689.7 Intensity: 0.0164 Position: 730.9 Intensity: 0.131 Position: 775.0Intensity: 0.0079 Position: 822.1 Intensity: 0.0673 Position: 832.5Intensity: 0.0444 Position: 849.1 Intensity: 0.0220 Position: 869.5Intensity: 0.0303 Position: 895.0 Intensity: 0.0155 Position: 961.0Intensity: 0.0124 Position: 1018.5 Intensity: 0.0269 Position: 1050.7Intensity: 0.0507 Position: 1067.0 Intensity: 0.0475 Position: 1079.2Intensity: 0.0572 Position: 1096.6 Intensity: 0.0507 Position: 1116.4Intensity: 0.0125 Position: 1147.6 Intensity: 0.0330 Position: 1178.7Intensity: 0.0124 Position: 1186.6 Intensity: 0.0121 Position: 1222.2Intensity: 0.0104 Position: 1255.1 Intensity: 0.0392 Position: 1296.0Intensity: 0.0642 Position: 1337.9 Intensity: 0.0111 Position: 1358.2Intensity: 0.0196 Position: 1378.5 Intensity: 0.0118 Position: 1386.5Intensity: 0.0117 Position: 1428.4 Intensity: 0.0350 Position: 1457.1Intensity: 0.0198 Position: 1480.7 Intensity: 0.0543 Position: 1510.6Intensity: 0.0257 Position: 1539.9 Intensity: 0.0085 Position: 1559.4Intensity: 0.0119 Position: 1581.7 Intensity: 0.0501 Position: 1623.0Intensity: 0.0215 Position: 1652.8 Intensity: 0.0077 Position: 1684.2Intensity: 0.0064 Position: 1733.8 Intensity: 0.0063 Position: 2360.9Intensity: 0.0063 Position: 2586.3 Intensity: 0.0081 Position: 2791.8Intensity: 0.0091 Position: 2838.4 Intensity: 0.0081 Position: 2879.0Intensity: 0.0088 Position: 2935.3 Intensity: 0.0091 Position: 2966.2Intensity: 0.0097 Position: 3074.6 Intensity: 0.0083 Position: 3098.3Intensity: 0.0079 Position: 3853.2 Intensity: 0.0067

FIG. 11 is the RAMAN spectrum of racemic ilaprazole, Form A. Table 7reports the absorbance peaks in the Raman spectrum.

TABLE 7 Peaks in the Raman Spectrum of Racemic Ilaprazole, Form A.Position: 419.0 Intensity: 0.382 Position: 448.1 Intensity: 0.489Position: 468.3 Intensity: 0.274 Position: 495.9 Intensity: 0.861Position: 513.6 Intensity: 1.139 Position: 537.3 Intensity: 1.416Position: 570.9 Intensity: 0.499 Position: 609.0 Intensity: 8.471Position: 626.0 Intensity: 1.247 Position: 647.6 Intensity: 0.750Position: 665.0 Intensity: 1.347 Position: 693.7 Intensity: 6.328Position: 713.2 Intensity: 3.418 Position: 733.4 Intensity: 0.611Position: 749.8 Intensity: 0.518 Position: 762.0 Intensity: 0.587Position: 776.3 Intensity: 1.559 Position: 815.9 Intensity: 3.102Position: 836.1 Intensity: 1.731 Position: 876.5 Intensity: 1.778Position: 900.1 Intensity: 1.031 Position: 938.8 Intensity: 0.483Position: 962.8 Intensity: 1.847 Position: 1019.7 Intensity: 2.473Position: 1056.0 Intensity: 0.873 Position: 1076.7 Intensity: 1.525Position: 1104.2 Intensity: 2.107 Position: 1119.9 Intensity: 3.057Position: 1149.1 Intensity: 0.500 Position: 1179.9 Intensity: 11.380Position: 1222.7 Intensity: 3.826 Position: 1251.2 Intensity: 4.911Position: 1266.1 Intensity: 12.991 Position: 1296.3 Intensity: 3.051Position: 1306.7 Intensity: 5.460 Position: 1337.8 Intensity: 24.178Position: 1358.5 Intensity: 2.454 Position: 1386.7 Intensity: 3.014Position: 1429.9 Intensity: 10.411 Position: 1457.9 Intensity: 4.703Position: 1483.8 Intensity: 2.072 Position: 1512.5 Intensity: 8.978Position: 1583.4 Intensity: 4.749 Position: 1623.7 Intensity: 9.033Position: 2839.0 Intensity: 1.219 Position: 2859.6 Intensity: 1.659Position: 2883.9 Intensity: 0.722 Position: 2935.4 Intensity: 4.143Position: 2966.2 Intensity: 1.164 Position: 2992.6 Intensity: 1.344Position: 3021.9 Intensity: 2.174 Position: 3063.9 Intensity: 2.400Position: 3075.3 Intensity: 3.810 Position: 3098.6 Intensity: 2.686Position: 3110.2 Intensity: 1.922 Position: 3130.6 Intensity: 3.377

FIG. 12 is the DVS isotherm of racemic ilaprazole, Form A. The DVSisotherm shows a 0.06% weight loss at 5% RH, a 0.10% weight gain from 5to 95% RH and a 0.13% weight loss from 95 to 5% RH.

A single crystal X-ray diffraction study of the structure of racemicilaprazole, Form A was done. The data was collected using colorlessplate of racemic ilaprazole, Form A having approximate dimensions of0.44×0.35×0.13 mm, which was mounted on a glass fiber in randomorientation. Preliminary examination and data collection were performedwith Mo K_(α) radiation (λ=0.71073 Å) on a Nonius KappaCCDdiffractometer. Refinements were performed on an LINUX PC using SHELX97.Sheldrick, G. M. SHELX97, A Program for Crystal Structure Refinement,University of Gottingen, Germany, 1997. The crystallographic drawingswere obtained using the programs ORTEP (Johnson, C. K. ORTEPIII, ReportORNL-6895, Oak Ridge National Laboratory, Tenn., U.S.A. 1996; OPTEP-3for Windows V 1.05, Farrugia, L. J., J. Appl. Cryst. 1997, 30, 565);CAMERON (Watkin, D. J.; Prout, C. K.; Pearce, L. J. CAMERON, ChemicalCrystallography Laboratory, University of Oxford, Oxford, 1996), andMercury (Bruno, I. J. Cole, J. C. Edgington, P. R. Kessler, M. K.Macrae, C. F. McCabe, P. Pearson, J. and Taylor, R. Acta Crystallogr.,2002 B58, 389).

Cell constants and an orientation matrix for data collection wereobtained from least-squares refinement using the setting angles of 8027reflections in the range 2°<θ<27°. The refined mosaicity fromDENZO/SCALEPACK (Otwinowski, Z.; Minor, W. Methods Enzymol. 1997, 276,307) is 0.54° indicating moderate crystal quality. The space group wasdetermined by the program XPREP. Bruker, XPREP in SHELXTL v. 6.12.,Bruker AXS Inc., Madison, Wis., USE, 2002. From the systematic presenceof the following conditions: 0k0 k=2n, and from subsequent least-squaresrefinement, the space group was determined to be P2₁ (no. 4). The datawere collected to a maximum 2θ value of 54.9°, at a temperature of 150±1K.

The data reduction was done as follows: Frames were integrated withDENZO-SMN. Otwinoski et al., supra. A total of 8027 reflections werecollected, of which 3676 were unique. Lorentz and polarizationcorrections were applied to the data. The linear absorption coefficientwas 2.0 cm⁻¹ for Mo K_(α) radiation. An empirical absorption correctionusing SCALEPACK (Otwinoski et al., supra) was applied. Transmissioncoefficients ranged from 0.94 to 0.98. Intensities of equivalentreflections were averaged. The agreement factor for the averaging was4.3% based on intensity.

The structure was solved by direct methods using SIR2004. Burla, M. C.,Caliandro, R., Camalli, M., Carrozzini, B., Cascarano, G. L., De Caro,L., Giacovazzo, C., Polidori, G., and Spagna, R., J. Appl. Cryst. 2005,38, 381. The remaining atoms were located in succeeding differenceFourier syntheses. Hydrogen atoms were included in the refinement butrestrained to ride on the atom to which they are bonded. The structurewas refined in full-matrix least-squares by minimizing the function:Σw(|F _(o)|² −|F _(c)|²)²The weight w is defined as 1/[σ²(F_(o) ²)+(0.0507P)²+(0.0000P)], whereP=(F_(o) ²+2F_(c) ²)/3.

Scattering factors were taken from the “International Tables forCrystallography.” International Tables for Crystallography, Vol. C,Kluwer Academic Publishers: Dordrecht, The Netherlands, 1992, Tables4.2.6.8 and 6.1.1.4. Of the 3676 reflections used in the refinements,only the reflections with F_(o) ²>2σ(F_(o) ²) were used in calculatingR. A total of 2844 reflections were used in the calculation. The finalcycle of refinement included 252 variable parameters and converged(largest parameter shift was approximately equal to its estimatedstandard deviation) with unweighted and weighted agreement factors of:R=Σ|F _(o) −F _(c) |/ΣF _(o)=0.041R _(w)=√{square root over ((Σw(F _(o) ² −F _(c) ²)² /Σw(F _(o)²)²))}{square root over ((Σw(F _(o) ² −F _(c) ²)² /Σw(F _(o)²)²))}=0.091

The standard deviation of an observation, of unit weight was 1.014. Thehighest peak in the final difference Fourier had a height of 0.22 e/Å³.The minimum negative peak had a height of −0.30 e/Å³. The factor for thedetermination of the absolute structure (Flack, H. D. Acta Cryst. 1983,A39, 876) refined to −0.04(8).

A calculated XRPD pattern was generated for Cu radiation using Mercury1.3 and the atomic coordinates, space group, and unit cell parametersfrom the single crystal data.

A summary of the crystal data and crystallographic data collectionparameters for racemic ilaprazole Form A are provided in Table 8. Themonoclinic cell parameters and calculated volume are: a=10.8006(9) Å,b=7.3333(3) Å, c=11.5247(10) Å, α=90.00°, β=107.261(4)°, γ=90.00°,V=871.69(11) Å³. The formula weight of ilaprazole Form A is 366.44g/mol, with Z=2 and a calculated density of 1.396 g cm⁻³. The spacegroup was determined to be P2₁. The quality of the structure obtained ishigh, as indicated by the R-value of 0.041 (4.1%). Usually R-values inthe range of 0.02 to 0.06 are quoted for the most reliably determinedstructures.

TABLE 8 Single Crystal Data and Data Collection Parameters for RacemicIlaprazole, Form A. formula C₁₉H₁₈N₄O₂S formula weight 366.44 spacegroup P2₁ (No. 4) a, Å 10.8006(9) b, Å  7.3333(3) c, Å  11.5247(10) b,deg 107.261(4) V, Å³  871.69(11) Z 2 d_(calc), g cm⁻³ 1.396 crystaldimensions, mm 0.44 × 0.35 × 0.13 temperature, K 150 radiation(wavelength, Å) Mo K_(a) (0.71073) monochromator graphite linear abscoef, mm⁻¹ 0.198 absorption correction applied empirical^(a)transmission factors: min, max 0.94, 0.98 diffractometer Nonius KappaCCDh, k, l range −13 to 14 −8 to 8 −14 to 14 2θ range, deg 4.54-54.94mosaicity, deg 0.54 programs used SHELXTL F₀₀₀ 384.0 weighting1/[σ²(F_(o) ²) + (0.0507P)² + 0.0000P] where P = (F_(o) ² + 2F_(c) ²)/3data collected 8027 unique data 3676 R_(int) 0.043 data used inrefinement 3676 cutoff used in R-factor calculations F_(o) ² >2.0σ(F_(o) ²) data with I > 2.0σ(I) 2844 refined extinction coef 0.0300number of variables 252 largest shift/esd in final cycle 0.01 R(F_(o))0.041 R_(w)(F_(o) ²) 0.091 goodness of fit 1.014 absolute structuredetermination Flack parameter^(b) (−0.04(8)) ^(a)Otwinowski Z. & Minor,W. Methods Enzymol., 1997, 276, 307. ^(b)Flack, H. D. Acta Cryst., 1983A39, 876.

An ORTEP drawing of racemic ilaprazole form A is shown in FIG. 13. Atomsare represented by 50% probability anisotropic thermal ellipsoids. Notethat the appearance of the second oxygen affixed to the sulfinyl groupis a representation of the disorder most likely caused by the presenceof both enantiomers in the unit cell. The occupancy of the enantiomerswas refined to approximately a 75:25 ratio. The major enantiomer isrepresented with a solid bond between S2 and O2a and the minorenantiomer with a hollow bond between S2 and O2b, respectively. Thematerial appears to be a member of a rare class of racemic compoundswhere the stoichiometry of the two enantiomers is not a 1:1 ratio. Thisclass of compounds is sometimes referred to “anomalous” racemates. Theasymmetric unit shown in FIG. 14 contains a single ilaprazole moleculeexhibiting a packing arrangement where every fourth molecule is theminor enantiomer.

Packing diagrams viewed along the a, b, and c crystallographic axes areshown in FIGS. 14-16 respectively. The packing arrangement in the Form Acrystal structure can be described as sheets of ilaprazole moleculesrunning perpendicular to the crystallographic b axis (FIG. 15). Thecalculated density of the Form A crystal structure (1.396 g cm⁻³) isslightly higher that the Form F crystal structure (1.391 g cm⁻³),suggesting Form A would be the more stable form at 150 K.

Hydrogen bonds are observed between the secondary amine (N3) of thebenzimidazole ring of one ilaprazole molecule to the pyridine nitrogen(N26) of an adjacent ilaprazole molecule. This hydrogen-bonding networkforms sheets of ilaprazole molecules that are rotated approximately 90°from each other, resulting in a one-dimensional hydrogen bondingnetwork. Closer examination of the structure reveals two close contactsbetween the two oxygen sites of the sulfinyl group. There is a closecontact of approximately 3.4 Å between the oxygen atom of the majorenantiomer (O2a) and the nitrogen atom secondary amine (N3) of thebenzimidazole group. This is not a hydrogen bonding interaction becausethe hydrogen atom in not in a position to interact with the sulfinyloxygen. The second close contact of approximately 3.3 Å between theoxygen atom of the minor enantiomer (O2b) and the ether linkage mightactually be a slightly repulsive interaction due to the lone pairs. Noother potential interactions were observed in the crystal structure.

FIG. 17 shows a calculated XRPD pattern of ilaprazole, generated fromthe single crystal data. The experimental XRPD pattern of ilaprazoleForm A is shown in FIG. 5. FIG. 18 shows a comparison of the calculatedXRPD pattern to the experimental pattern of racemic ilaprazole Form A.All peaks in the experimental patterns are represented in the calculatedXRPD pattern, indicating the bulk material is likely a single phase. Theslight shifts in peak location are likely due to the fact that theexperimental powder pattern was collected at ambient temperature, andthe single crystal data was collected at 150 K. Low temperatures areused in single crystal analysis to improve the quality of the structure.

If the material was a single enantiomer, the absolute configuration ofthe molecule would be determined by analysis of anomalous X-rayscattering by the crystal. The differences in intensities of theanomalous scattering are then compared with calculated scatteringintensities for each enantiomer. These measured and calculatedintensities can then be fit to a parameter, the Flack factor. Becauseeach crystal contains a mixture of enantiomers and therefore is notenantiopure, the absolute configuration of the model in FIG. 13 cannotbe uniquely determined with the current data set.

Example 3 Preparation and Characterization of Racemic Ilaprazole, Form F

Approximately 153.4 mg racemic ilaprazole Form A was added to a solutioncontaining 3 mL dichloromethane (DCM) and 10 μL triethylamine (TEA). Thesolid was dissolved using sonication. The solution was filtered througha 0.2 micron nylon filter into a glass vial and left to evaporate atambient room temperature. A lightly colored solid resulted approximately1 day later, which was identified as Form F.

Racemic ilaprazole, Form F was also prepared by the following procedure.Racemic ilaprazole (0.5 g, Form A) was slurried in EtOH/10% water (5 mL,10 volumes) and was stirred at 0° C. for 24 h. The resulting solids wereisolated by filtration and dried under vacuum at 40° C. to afford 0.44 gof Form K; 87.8% recovery. Racemic ilaprazole (40 mg, Form K) was thenslurried in anhydrous EtOH (2 mL, 50 vol) and stirred at temperaturesranging from 5 to 20° C. for 24 h. The obtained solids were isolated byfiltration and dried under vacuum at 40° C. to afford Form F. A slurrytemperature of 6° C. is preferred.

The XRPD pattern of racemic ilaprazole, Form F was obtained using anInel XRG-3000 diffractometer, as described above. The measurementconditions are reported in Table 9. FIG. 19 shows the XRPD pattern forracemic ilaprazole, Form F. Table 10 reports the peaks identified in theXRPD pattern. In its XRPD racemic ilaprazole, Form F may becharacterized by peaks at 9.4°2θ±0.2°2θ; 17.5°2θ±0.2°2θ; 18.8°2θ±0.2°2θand 32.8°2θ±0.2°2θ. Another characteristic grouping includes peaks at7.9°2θ±0.2°2θ; 28.8°2θ±0.2°2θ; 30.5°2θ±0.2°2θ; 31.9°2θ±0.2°2θ and35.8°2θ±0.2°2θ.

TABLE 9 Measurement Conditions for XRPD Pattern of Racemic Ilaprazole,Form F Measurement Condition: X-ray tube target = Cu voltage = 40.0 (kV)current = 30.0 (mA) Slits divergence slit = 1.00000 (deg) scatter slit =1.00000 (deg) receiving slit = 0.15000 (mm) Scanning drive axis =2Theta/Theta scan range = 2.507-39.987 scan mode = Continuous Scan scanspeed = 0.0040 (deg/min) sampling pitch = 0.0200 (deg) preset time =300.00 (sec) Data Process Condition: Smoothing [AUTO] smoothing points =11 B.G. Subtraction [AUTO] sampling points = 13 repeat times = 30 Ka1-a2Separate [MANUAL] Ka1 a2 ratio = 50.0 (%) Peak Search [AUTO]differential points = 11 FWHM threshold = 0.050 (deg) intensitythreshold = 30 (par mil) FWHM ratio (n − 1)/n = 2 System ErrorCorrection: [NO] Precise Peak Correction: [NO]

TABLE 10 Peak Positions of Racemic Ilaprazole, Form F XRPD PatternPosition Peak (°2θ ± 0.2 No. °2θ) d-spacing Intensity I/I_(o) 1 7.9 11.2614 22 2 8.5 10.4 1619 59 3 9.4 9.4 784 29 4 14.6 6.1 184 7 5 14.9 5.9142 5 6 15.1 5.8 90 3 7 15.4 5.7 135 5 8 15.8 5.6 2600 95 9 17.5 5.1 50518 10 18.8 4.7 752 27 11 19.2 4.6 114 4 12 19.5 4.5 89 3 13 20.0 4.4 75728 14 20.3 4.4 616 22 15 20.6 4.3 166 6 16 21.0 4.2 2742 100 17 22.5 3.91327 48 18 23.5 3.8 763 28 19 23.7 3.7 242 9 20 24.6 3.6 339 12 21 25.03.6 124 5 22 25.9 3.4 102 4 23 26.8 3.3 170 6 24 27.1 3.3 465 17 25 27.83.2 196 7 26 28.5 3.1 118 4 27 28.8 3.1 114 4 28 29.5 3.0 184 7 29 29.83.0 212 8 30 30.1 3.0 157 6 31 30.5 2.9 135 5 32 31.9 2.8 229 8 33 32.82.7 278 10 34 33.1 2.7 198 7 35 35.8 2.5 85 3

FIG. 20 is the TGA thermogram of racemic ilaprazole, Form F. The sampleshowed a 2.4% weight loss up to 150° C.

FIG. 21 is the DSC thermogram of racemic ilaprazole, Form F. Theendotherm onset was at 170° C. (max 173° C.).

FIG. 22 is the proton NMR Spectrum of racemic ilaprazole, Form F. Anypeaks near 5.32 ppm are due to solvent—not to ilaprazole. Peaks near 1.0and 2.5 ppm are due to TEA, which is used to stabilize ilaprazole insolution, and not to ilaprazole.

FIG. 23 is the solid state ¹³C CP/MAS NMR spectrum of racemicilaprazole, Form F. The spectrum is externally referenced againstglycine at 176.5 ppm. The peaks in the solid state ¹³C NMR spectrum arereported in Table 11.

TABLE 11 Solid State ¹³C NMR Peaks for Racemic Ilaprazole, Form F. PPMHEIGHT 164.2 72.4 156.2 64.0 148.4 104.2 143.2 75.7 137.4 141.8 121.2137.2 110.4 79.1 107.7 55.2 60.3 54.1 56.3 103.3 10.5 95.9

FIG. 24 is the IR spectrum of racemic ilaprazole, Form F. Table 12reports the absorbance peaks in the IR spectrum.

TABLE 12 Peaks in IR Spectrum of Racemic Ilaprazole, Form F. Position:721.3 Intensity: 0.0746 Position: 817.9 Intensity: 0.0384 Position:833.0 Intensity: 0.0296 Position: 876.1 Intensity: 0.0125 Position:895.1 Intensity: 0.0074 Position: 962.0 Intensity: 0.0038 Position:1015.9 Intensity: 0.0209 Position: 1052.9 Intensity: 0.0308 Position:1064.8 Intensity: 0.0289 Position: 1080.3 Intensity: 0.0402 Position:1096.5 Intensity: 0.0355 Position: 1148.8 Intensity: 0.0160 Position:1187.3 Intensity: 0.0042 Position: 1221.1 Intensity: 0.0034 Position:1255.0 Intensity: 0.0246 Position: 1295.2 Intensity: 0.0398 Position:1337.4 Intensity: 0.0022 Position: 1358.8 Intensity: 0.0081 Position:1379.3 Intensity: 0.0050 Position: 1434.2 Intensity: 0.0183 Position:1454.8 Intensity: 0.0053 Position: 1478.4 Intensity: 0.0278 Position:1509.7 Intensity: 0.0124 Position: 1580.8 Intensity: 0.0293 Position:1623.1 Intensity: 0.0073 Position: 1723.7 Intensity: 0.00054 Position:1903.9 Intensity: 0.00058 Position: 2587.5 Intensity: 0.0022 Position:2794.3 Intensity: 0.0028 Position: 2841.0 Intensity: 0.0022 Position:2881.5 Intensity: 0.0026 Position: 2971.7 Intensity: 0.0038 Position:3011.4 Intensity: 0.0030 Position: 3072.9 Intensity: 0.0032 Position:3100.8 Intensity: 0.0027 Position: 3735.3 Intensity: 0.0010

FIG. 25 is the RAMAN spectrum of racemic ilaprazole, Form F. Table 13reports the absorbance peaks in the Raman spectrum.

TABLE 13 Peaks in the Raman Spectrum of Racemic Ilaprazole, Form FPosition: 100.2 Intensity: 2.257 Position: 122.9 Intensity: 2.700Position: 171.0 Intensity: 1.653 Position: 238.3 Intensity: 1.247Position: 311.8 Intensity: 1.028 Position: 441.9 Intensity: 1.048Position: 511.4 Intensity: 1.464 Position: 533.6 Intensity: 1.198Position: 610.5 Intensity: 6.403 Position: 694.6 Intensity: 4.080Position: 715.5 Intensity: 2.084 Position: 778.0 Intensity: 1.180Position: 816.8 Intensity: 2.217 Position: 877.2 Intensity: 1.112Position: 898.2 Intensity: 0.895 Position: 970.7 Intensity: 1.336Position: 1020.8 Intensity: 1.520 Position: 1081.5 Intensity: 1.116Position: 1101.4 Intensity: 1.434 Position: 1122.2 Intensity: 1.769Position: 1182.2 Intensity: 5.141 Position: 1222.7 Intensity: 2.099Position: 1269.0 Intensity: 6.256 Position: 1298.6 Intensity: 2.538Position: 1312.2 Intensity: 2.544 Position: 1338.4 Intensity: 15.434Position: 1360.2 Intensity: 1.596 Position: 1383.9 Intensity: 1.700Position: 1432.8 Intensity: 5.905 Position: 1460.3 Intensity: 2.586Position: 1511.7 Intensity: 5.232 Position: 1582.7 Intensity: 2.970Position: 1624.4 Intensity: 4.880 Position: 2842.4 Intensity: 1.136Position: 2934.0 Intensity: 3.251 Position: 3014.8 Intensity: 2.247Position: 3073.7 Intensity: 4.180 Position: 3103.0 Intensity: 2.744Position: 3131.0 Intensity: 1.871 Position: 3150.4 Intensity: 1.583

FIG. 26 is the DVS isotherm of racemic ilaprazole, Form F. The DVSisotherm shows a 0.04% weight loss at 5% RH, a 1.05% weight gain from 5to 95% RH, and a 1.33% weight loss from 95 to 5% RH.

A single crystal X-ray diffraction study of racemic ilaprazole, Form Fwas done using crystals obtained from a acetone/methylene chloridesolution. A solution of ilaprazole (˜35.8 mg) and piperazine (˜10.4 mg)was prepared in a solvent mixture of acetone (2.0 mL) and methylenechloride (0.5 mL) at room temperature. Hexanes (5.0 mL) were added toprovide a turbid solution. The vial was sealed and the solution wasleft, undisturbed, at ambient conditions. Racemic ilaprazole, Form Fcrystals were observed after six days were subsampled from the parentsample.

The data was collected using a colorless needle of racemic ilaprazole,Form F having approximate dimensions of 0.44×0.13×0.10 mm, which wasmounted on a glass fiber in random orientation. Preliminary examinationand data collection were performed with Mo K_(α) radiation (λ=0.71073 Å)on a Nonius KappaCCD diffractometer. Refinements were performed on anLINUX PC using SHELX97. Sheldrick, G. M. SHELX97, A Program for CrystalStructure Refinement, University of Gottingen, Germany, 1997.

Cell constants and an orientation matrix for data collection wereobtained from least-squares refinement using the setting angles of 22729reflections in the range 2°<θ<27°. The refined mosaicity fromDENZO/SCALEPACK (Otwinowski, Z.; Minor, W. Methods Enzymol. 1997, 276,307) is 0.85° indicating moderate to poor crystal quality. The spacegroup was determined by the program XPREP. Bruker, XPREP in SHELXTL v.6.12., Bruker AXS Inc., Madison, Wis., USE, 2002. From the systematicpresence of the following conditions: h0l h+l=2n, 0k0 k=2n and fromsubsequent least-squares refinement, the space group was determined tobe P2₁/n (no. 14). The data were collected to a maximum 2θ value of54.94°, at a temperature of 150±1 K.

The data reduction was accomplished as follows. The frames wereintegrated with DENZO-SMN. Otwinowski, et al. supra. A total of 22729reflections were collected, of which 2277 were unique. Lorentz andpolarization corrections were applied to the data. The linear absorptioncoefficient is 2.0 cm⁻¹ for Mo K_(α) radiation. An empirical absorptioncorrection using SCALEPACK (Otwinowski, et al. supra). was applied.Transmission coefficients ranged from 0.912 to 0.981. Intensities ofequivalent reflections were averaged. A secondary extinction correctionwas applied. The final coefficient, refined in least-squares, was0.0010000 (in absolute units). The agreement factor for the averagingwas 5.4% based on intensity.

The structure was solved by direct methods using PATTY in DIRDIF99. P.T. Beurskens, G. Beurskens, R. deGelder S. Garcia-Granda, R. O. Gould,R. Israel and J. M. M. Smits, The DIRDIF-99 Program System.Crystallography Laboratory, Univ. of Nijmegen, The Netherlands, 1999.The remaining atoms were located in succeeding difference Fouriersyntheses. Hydrogen atoms were included in the refinement but restrainedto ride on the atom to which they are bonded. The structure was refinedin full-matrix least-squares by minimizing the function:Σw(|F _(o)|² −|F _(c)|²)²The weight w is defined as 1/[σ²(F_(o) ²)+(0.1403P)²+(0.5425P)], whereP=(F_(o) ²+2F_(c) ²)/3.

Scattering factors were taken from the “International Tables forCrystallography.” International Tables for Crystallography, Vol. C,Kluwer Academic Publishers: Dordrecht, The Netherlands, 1992, Tables4.2.6.8 and 6.1.1.4. Of the 2277 reflections used in the refinements,only the reflections with F_(o) ²>2σ(F_(o) ²) were used in calculatingR. A total of 1706 reflections were used in the calculation. The finalcycle of refinement included 252 variable parameters and converged(largest parameter shift was essentially equal to its estimated standarddeviation) with unweighted and weighted agreement factors of:R=Σ|F _(o) −F _(c) |/ΣF _(o)=0.066R _(w)=√{square root over ((Σw(F _(o) ² −F _(c) ²)² /Σw(F _(o)²)²))}{square root over ((Σw(F _(o) ² −F _(c) ²)² /Σw(F _(o)²)²))}=0.174The standard deviation of an observation of unit weight was 1.07. Thehighest peak in the final difference Fourier had a height of 0.63 e/Å³.The minimum negative peak had a height of −0.46 e/Å³.

A calculated XRPD pattern was generated for Cu K_(α) radiation usingMercury v 1.3 (Bruno, I. J. Cole, J. C. Edgington, P. R. Kessler, M. K.Macrae, C. F. McCabe, P. Pearson, J. and Taylor, R. Acta Crystallogr.,2002 B58, 389) and the atomic coordinates, space group, and unit cellparameters from the single crystal data.

The ORTEP diagram was prepared using ORTEP III. Johnson, C. K. ORTEPIII,Report ORNL-6895, Oak Ridge National Laboratory, Tenn., U.S.A. 1996.OPTEP-3 for Windows V1.05, Farrugia, L. J., J. Appl. Cryst. 1997, 30,565. Atoms are represented by 50% probability anisotropic thermalellipsoids. Packing diagrams were prepared using CAMERON (Watkin, D. J.;Prout, C. K.; Pearce, L. J. CAMERON, Chemical CrystallographyLaboratory, University of Oxford, Oxford, 1996) modeling software.Hydrogen bonding is represented as dashed lines. Additional figures weregenerated using Mercury 1.3 modeling software.

A summary of the crystal data and crystallographic data collectionparameters for racemic ilaprazole Form F are provided in Table 14. Themonoclinic cell parameters and calculated volume are: a=11.8469(8) Å,b=7.2242(3) Å, c=20.9109(16) Å, α=90.00°, β=102.224(3)°, γ=90.00°,V=1749.07(19) Å³. The formula weight of ilaprazole, Form F is 366.44g/mol and with Z=4 gives a calculated density of 1.391 g cm⁻³. The spacegroup was determined to be P2₁/n. The quality of the structure obtainedis moderate, as indicated by the R-value of 0.066 (6.6%). UsuallyR-values in the range of 0.02 to 0.06 are quoted for the most reliablydetermined structures. Glusker, Jenny Pickworth; Trueblood, Kenneth N.Crystal Structure Analysis: A Primer, 2^(nd) ed.; Oxford Universitypress: New York, 1985; p. 87.

TABLE 14 Single Crystal Data and Data Collection Parameters forIlaprazole, Form F formula C₁₉H₁₈N₄O₂S formula weight 366.44 space groupP2₁/n (No. 14) a, Å 11.8469(8) b, Å  7.2242(3) c, Å  20.9109(16) β, deg102.224(3) V, Å³  1749.07(19) Z 4 d_(calc), g cm⁻³ 1.391 crystaldimensions, mm 0.44 × 0.13 × 0.10 temperature, K 150. radiation(wavelength, Å) Mo K_(a) (0.71073) monochromator graphite linear abscoef, mm⁻¹ 0.197 absorption correction applied empirical^(a)transmission factors: min, max 0.912, 0.981 diffractometer NoniusKappaCCD h, k, l range 0 to 15 0 to 9 −27 to 26 2θ range, deg 4.73-54.95mosaicity, deg 0.85 programs used SHELXTL F₀₀₀ 768.0 weighting1/[σ²(F_(o) ²) + (0.1403P)² + 0.5425P] where P = (F_(o) ² + 2F_(c) ²)/3data collected 22729 unique data 2277 R_(int) 0.054 data used inrefinement 2277 cutoff used in R-factor calculations F_(o) ² >2.0σ(F_(o) ²) data with I > 2.0σ(I) 1706 refined extinction coef 0.0010number of variables 252 largest shift/esd in final cycle 0.00 R(F_(o))0.066 R_(w)(F_(o) ²) 0.174 goodness of fit 1.072 ^(a)Otwinowski Z. &Minor, W. Methods Enzymol., 1997, 276, 307.

An ORTEP drawing of racemic ilaprazole, Form F is shown in FIG. 27.Atoms are represented by 50% probability anisotropic thermal ellipsoids.The oxygen atom of the sulfinyl group is disordered due to the presenceof both enantiomers in the unit cell. The occupancy of the enantiomerswas refined to a ratio of approximately 86:14. The ORTEP diagram (FIG.27) highlights the major enantiomer with a solid bond between S2 andO10a and the minor enantiomer with a hollow bond between S2 and O10b,respectively. The material appears to be an example of a rare class ofcompounds called “anomalous” racemates, where the stoichiometry of thetwo enantiomers is not a 1:1 ratio.

Packing diagrams viewed along the a, b, and c crystallographic axes areshown in FIGS. 28-30 respectively. The packing arrangement of ilaprazolemolecules in the Form F crystal structure can be described as sheets ofilaprazole molecules running perpendicular to the crystallographic baxis (FIG. 29). Overlaying the ilaprazole molecule from this crystalstructure (FIG. 27) and the ilaprazole molecule from the Form A crystalstructure (FIG. 13) showed significant conformational similarity of theilaprazole molecule in the two crystal structures. The Form F crystalstructure consists of layers of ilaprazole molecules packing in aalternating ABAB arrangement.

Hydrogen bonds were observed between the secondary amine (N3) of thebenzimidazole ring of one ilaprazole molecule to the pyridine nitrogen(N16) of an adjacent molecule, resulting in a similar hydrogen bondingpattern observed for racemic ilaprazole, Form A. Closer examination ofthe structure reveals two close contacts between the two oxygen sites ofthe sulfinyl group. There is a close contact of approximately 3.2 Åbetween the oxygen atom of the major enantiomer (O10a) and the nitrogenatom secondary amine (N3) of the benzimidazole group. This is not apotential hydrogen bonding interaction because the hydrogen atom is notin a position to interact with the sulfinyl oxygen. The second closecontact of approximately 3.0 Å between the oxygen atom of the minorenantiomer (O10b) and the oxygen atom of the ether linkage (O131). Thisclose contact is probably a slightly repulsive interaction since theshorter distance (3.0 Å for Form F and 3.4 Å for Form A) appears to berelated to the occupancy of the minor enantiomer (˜14% for Form F and˜25% for Form A).

While the molecular conformations are very similar, the packing betweenthe two forms is different. The packing along the crystallographic baxis for racemic ilaprazole, Form A and Form F is shown in FIG. 31. Inthe Form A crystal structure, the layers run parallel to thecrystallographic c axis, while in Form F, the layers run perpendicularto the c axis. The layers propagate in an alternating fashion for theForm F crystal structure, accounting for the doubling of the c axisparameter. The calculated density of the Form A crystal structure (1.396g cm⁻³) is slightly higher that the Form F crystal structure (1.391 gcm⁻³), suggesting Form A would be more stable at 0 K.

FIG. 31 shows a calculated XRPD pattern of ilaprazole, From F, generatedfrom the single crystal data. The experimental XRPD pattern ofilaprazole, Form F is shown in FIG. 32 and a comparison of thecalculated and experimental powder diffraction patterns is shown in FIG.33. All peaks in the experimental patterns are represented in thecalculated XRPD pattern, indicating the bulk material is likely a singlephase. The slight shifts in peak location are likely due to the factthat the experimental powder pattern was collected at ambienttemperature, and the single crystal data was collected at 150 K. Lowtemperatures are used in single crystal analysis to improve the qualityof the structure.

Example 4 Preparation and Characterization of Racemic Ilaprazole, Form I

A solution containing 3 mL of methanol (MeOH) and 10 μL triethylamine(TEA) was saturated with racemic ilaprazole, Form A by sonicating withexcess solids for approximately 3 minutes. The resulting slurry wasfiltered through a 0.2 micron nylon filter into a glass vial. The vialwas capped and placed into the freezer. The resulting white solid wascollected by vacuum filtration approximately 2 days later as themethanol solvate, Form G, which is believed to be a variable solvate. Asmall spatula full of Form G (e.g. >30 mg) was placed in a 1 dram glassvial. The open vial was exposed to ambient temperature under vacuum. Awhite solid resulted approximately 1 day later as Form I.

The XRPD pattern of racemic ilaprazole, Form I was obtained using anInel XRG-3000 diffractometer, as described above. The measurementconditions are reported in Table 15. FIG. 34 shows the XRPD pattern forracemic ilaprazole, Form I. Table 16 reports the peaks identified in theXRPD pattern. In its XRPD racemic ilaprazole, Form I may becharacterized by peaks at 11.9°2θ±0.2°2θ; 17.1°2θ±0.2°2θ; 21.5°2θ±0.2°2θand 25.1°2θ±0.2°2θ. Another characteristic grouping includes peaks at5.9 2θ±0.2°2θ; 12.2 2θ±0.2°2θ, and 35.6 2θ±0.2°2θ.

TABLE 15 Measurement Conditions for XRPD Pattern of Racemic Ilaprazole,Form I. Measurement Condition: X-ray tube target = Cu voltage = 40.0(kV) current = 30.0 (mA) Slits divergence slit = 1.00000 (deg) scatterslit = 1.00000 (deg) receiving slit = 0.15000 (mm) Scanning drive axis =2Theta/Theta scan range = 2.507-39.987 scan mode = Continuous Scan scanspeed = 0.0040 (deg/min) sampling pitch = 0.0200 (deg) preset time =300.00 (sec) Data Process Condition: Smoothing [AUTO] smoothing points =11 B.G. Subtraction [AUTO] sampling points = 13 repeat times = 30 Ka1-a2Separate [MANUAL] Ka1 a2 ratio = 50.0 (%) Peak Search [AUTO]differential points = 11 FWHM threshold = 0.050 (deg) intensitythreshold = 30 (par mil) FWHM ratio (n − 1)/n = 2 System ErrorCorrection: [NO] Precise Peak Correction: [NO]

TABLE 16 Peak Positions of Ilaprazole, Form I XRPD Pattern Peak No.Position (°2θ ± 0.2 °2θ) d-spacing Intensity I/I_(o) 1 5.9 15.0 3236 1002 6.5 13.7 182 6 3 11.4 7.8 254 8 4 11.9 7.5 1453 45 5 12.2 7.2 100 3 613.0 6.8 101 3 7 15.1 5.8 174 5 8 15.8 5.6 142 4 9 16.2 5.5 198 6 1017.1 5.2 283 9 11 17.5 5.1 391 12 12 17.8 5.0 125 4 13 18.1 4.9 167 5 1420.6 4.3 402 12 15 21.5 4.1 458 14 16 21.7 4.1 183 6 17 24.6 3.6 180 618 25.1 3.5 618 19 19 25.3 3.5 207 6 20 25.7 3.5 219 7 21 35.6 2.5 98 3

FIG. 35 is the TGA thermogram of racemic ilaprazole, Form I. The sampleshowed a 0.9% weight loss up to 30° C. and 0.4% weight loss between 30and 120° C.

FIG. 36 is the DSC thermogram of racemic ilaprazole, Form I. Theendotherm onset occurred at 113° C. (max 134° C.).

FIG. 37 is the proton NMR Spectrum of racemic ilaprazole, Form I. Anypeaks near 5.32 ppm are due to solvent—not to ilaprazole. Peaks near 1.0and 2.5 ppm are due to TEA, which is used to stabilize ilaprazole insolution, and not to ilaprazole.

FIG. 38 is the IR spectrum of racemic ilaprazole, Form I. Table 17reports the absorbance peaks in the IR spectrum.

TABLE 17 Peaks in IR Spectrum of Racemic Ilaprazole, Form I. Position:716.8 Intensity: 0.0196 Position: 729.6 Intensity: 0.0262 Position:744.1 Intensity: 0.0620 Position: 780.3 Intensity: 0.0037 Position:810.6 Intensity: 0.0407 Position: 825.0 Intensity: 0.0488 Position:838.3 Intensity: 0.0278 Position: 857.0 Intensity: 0.0163 Position:880.8 Intensity: 0.0124 Position: 890.5 Intensity: 0.0160 Position:906.6 Intensity: 0.0124 Position: 951.5 Intensity: 0.0108 Position:960.8 Intensity: 0.0138 Position: 1015.6 Intensity: 0.0133 Position:1021.5 Intensity: 0.0128 Position: 1057.0 Intensity: 0.115 Position:1077.1 Intensity: 0.0548 Position: 1101.0 Intensity: 0.0396 Position:1151.4 Intensity: 0.0111 Position: 1193.5 Intensity: 0.0082 Position:1220.1 Intensity: 0.0099 Position: 1248.7 Intensity: 0.0217 Position:1259.9 Intensity: 0.0222 Position: 1267.8 Intensity: 0.0227 Position:1296.6 Intensity: 0.0558 Position: 1338.8 Intensity: 0.0042 Position:1359.1 Intensity: 0.0112 Position: 1375.5 Intensity: 0.0032 Position:1390.2 Intensity: 0.0072 Position: 1421.3 Intensity: 0.0266 Position:1462.3 Intensity: 0.0146 Position: 1482.5 Intensity: 0.0436 Position:1521.2 Intensity: 0.0148 Position: 1585.4 Intensity: 0.0487 Position:1627.3 Intensity: 0.0103 Position: 1774.6 Intensity: 0.00059 Position:1869.5 Intensity: 0.00049 Position: 2589.6 Intensity: 0.0052 Position:2658.0 Intensity: 0.0045 Position: 2751.5 Intensity: 0.0046 Position:2841.8 Intensity: 0.0040 Position: 2876.7 Intensity: 0.0039 Position:2937.2 Intensity: 0.0079 Position: 2980.8 Intensity: 0.0079 Position:3006.7 Intensity: 0.0040 Position: 3095.2 Intensity: 0.0030 Position:3481.1 Intensity: 0.00066

FIG. 39 is the RAMAN spectrum of racemic ilaprazole, Form I. Table 18reports the absorbance peaks in the Raman spectrum.

TABLE 18 Peaks in the Raman Spectrum of Racemic Ilaprazole, Form I.Position: 402.5 Intensity: 6.251 Position: 423.4 Intensity: 4.046Position: 439.3 Intensity: 6.695 Position: 467.2 Intensity: 1.280Position: 508.9 Intensity: 6.226 Position: 537.0 Intensity: 7.294Position: 575.9 Intensity: 2.058 Position: 602.1 Intensity: 14.741Position: 608.4 Intensity: 19.813 Position: 625.0 Intensity: 3.686Position: 641.3 Intensity: 0.343 Position: 671.9 Intensity: 6.680Position: 687.4 Intensity: 10.109 Position: 705.1 Intensity: 18.324Position: 715.2 Intensity: 40.085 Position: 746.3 Intensity: 0.223Position: 757.2 Intensity: 0.657 Position: 779.3 Intensity: 13.833Position: 814.4 Intensity: 7.625 Position: 824.3 Intensity: 3.724Position: 839.5 Intensity: 3.268 Position: 858.2 Intensity: 0.596Position: 872.3 Intensity: 2.936 Position: 883.2 Intensity: 3.271Position: 892.6 Intensity: 2.679 Position: 906.6 Intensity: 3.272Position: 937.9 Intensity: 0.628 Position: 964.6 Intensity: 12.167Position: 1022.4 Intensity: 5.498 Position: 1058.4 Intensity: 8.147Position: 1078.3 Intensity: 11.286 Position: 1105.5 Intensity: 12.333Position: 1122.2 Intensity: 13.568 Position: 1153.0 Intensity: 1.822Position: 1195.6 Intensity: 18.478 Position: 1218.6 Intensity: 11.741Position: 1248.5 Intensity: 17.145 Position: 1271.0 Intensity: 66.038Position: 1298.3 Intensity: 19.951 Position: 1312.9 Intensity: 12.236Position: 1338.2 Intensity: 115.936 Position: 1390.7 Intensity: 14.399Position: 1430.2 Intensity: 33.921 Position: 1463.4 Intensity: 22.573Position: 1486.0 Intensity: 7.195 Position: 1520.5 Intensity: 33.708Position: 1585.5 Intensity: 21.258 Position: 1628.5 Intensity: 27.280Position: 2537.6 Intensity: 0.355 Position: 2738.6 Intensity: 1.268Position: 2842.7 Intensity: 10.481 Position: 2938.7 Intensity: 35.252Position: 2980.1 Intensity: 25.665 Position: 3007.6 Intensity: 10.180Position: 3065.6 Intensity: 19.538 Position: 3095.0 Intensity: 20.168Position: 3106.6 Intensity: 13.334 Position: 3127.2 Intensity: 14.441

FIG. 40 is the DVS isotherm of racemic ilaprazole, Form I. The DVSisotherm shows a 0.1% weight loss at 5% RH, a 4.2% weight gain from 5 to95% RH, and a 4.2% weight loss from 95 to 5% RH.

Example 5 Preparation of Characterization of Racemic Ilaprazole, Form B

A solution containing 10 mL of acetone was saturated with ilaprazole,Form A by sonicating with excess solids for approximately 5 minutes atambient temperature. The resulting slurry was filtered through a 0.2micron nylon filter into a glass vial. The vial was capped and placedinto a refrigerator. The resulting white solid was collected by vacuumfiltration 11 days later as Form B.

The XRPD pattern of racemic ilaprazole, Form B was obtained using anInel XRG-3000 diffractometer, as described above. The measurementconditions are reported in Table 19. FIG. 41 shows the XRPD pattern forracemic ilaprazole, Form B. Table 20 reports the peaks identified in theXRPD pattern. In its XRPD racemic ilaprazole Form B may be characterizedby peaks at 6.8°2θ±0.2°2θ; 9.1°2θ±0.2°2θ; 22.0°2θ±0.2°2θ and25.5°2θ±0.2°2θ. Another characteristic grouping includes peaks at 3.72θ±0.2°2θ; 6.0°2θ±0.2°2θ; 6.8 2θ±0.2°2θ; 9.1 2θ±0.2°2θ; 12.1 2θ±0.2°2θ;and 31.4 2θ±0.2°2θ.

TABLE 19 Measurement Conditions for XRPD Pattern of Racemic Ilaprazole,Form B. Measurement Condition: X-ray tube target = Cu voltage = 40.0(kV) current = 30.0 (mA) Slits divergence slit = 1.00000 (deg) scatterslit = 1.00000 (deg) receiving slit = 0.15000 (mm) Scanning drive axis =2Theta/Theta scan range = 2.519-39.979 scan mode = Continuous Scan scanspeed = 0.0040 (deg/min) sampling pitch = 0.0200 (deg) preset time =300.00 (sec) Data Process Condition: Smoothing [AUTO] smoothing points =23 B.G. Subtraction [AUTO] sampling points = 27 repeat times = 30 Ka1-a2Separate [MANUAL] Ka1 a2 ratio = 50.0 (%) Peak Search [AUTO]differential points = 21 FWHM threshold = 0.050 (deg) intensitythreshold = 30 (par mil) FWHM ratio (n − 1)/n = 2 System ErrorCorrection: [NO] Precise Peak Correction: [NO]

TABLE 20 Peak Positions of Ilaprazole, Form B XRPD Pattern Peak No.Position (°2θ ± 0.2 °2θ) d-spacing Intensity I/I_(o) ^(c) 1 3.7 23.9 444 2 6.0 14.8 48 4 3 6.8 12.9 1227 100 4 9.1 9.7 114 9 5 11.8 7.5 73 6 612.1 7.3 56 5 7 12.6 7.0 315 26 8 14.8 6.0 114 9 9 15.8 5.6 537 44 1018.1 4.9 258 21 11 19.4 5.6 156 13 12 20.2 4.4 148 12 13 20.7 4.3 70 614 21.2 4.2 413 34 15 22.0 4.0 357 29 16 22.7 3.9 124 10 17 23.2 3.8 13311 18 23.6 3.8 362 30 19 24.1 3.7 317 26 20 24.4 3.6 177 14 21 25.5 3.5417 34 22 26.7 3.3 67 5 23 27.2 3.3 101 8 24 27.8 3.2 87 7 25 29.1 3.184 7 26 31.4 2.8 66 5

FIG. 42 is the TGA thermogram of racemic ilaprazole, Form B. The sampleshowed a 0.2% weight loss up to 150° C. and 5.8% weight loss between 150and 175° C.

FIG. 43 is the DSC thermogram of racemic ilaprazole, Form B. Theendotherm onset occurred at 159° C. (max 163° C.).

FIG. 44 is the proton NMR Spectrum of racemic ilaprazole, Form B. Anypeaks near 5.32 ppm are due to solvent—not to ilaprazole. Peaks near 1.0and 2.5 ppm are due to TEA, which is used to stabilize ilaprazole insolution, and not to ilaprazole.

FIG. 45 is the solid state ¹³C CP/MAS NMR spectrum of racemicilaprazole, Form B. The spectrum is externally referenced againstglycine at 176.5 ppm. The peaks in the solid state ¹³C NMR spectrum arereported in Table 21.

TABLE 21 Solid State ¹³C NMR Peaks for Racemic Ilaprazole, Form B. PPMHEIGHT 163.5 99.8 155.0 62.2 152.2 77.5 149.5 58.7 142.2 80.6 135.7104.3 121.5 65.4 118.3 141.8 116.2 88.5 110.3 53.5 107.8 44.0 104.5 94.355.7 117.1 11.5 85.4

FIG. 46 is the IR spectrum of racemic ilaprazole, Form B. Table 22reports the absorbance peaks in the IR spectrum.

TABLE 22 Peaks in IR Spectrum of Racemic Ilaprazole Form B. Position:715.4 Intensity: 0.0125 Position: 732.2 Intensity: 0.0730 Position:758.2 Intensity: 0.0131 Position: 810.3 Intensity: 0.0464 Position:829.0 Intensity: 0.0126 Position: 864.1 Intensity: 0.0100 Position:892.2 Intensity: 0.0101 Position: 953.4 Intensity: 0.0053 Position:971.1 Intensity: 0.0089 Position: 1014.2 Intensity: 0.0154 Position:1043.6 Intensity: 0.0534 Position: 1058.1 Intensity: 0.0339 Position:1069.6 Intensity: 0.0229 Position: 1088.9 Intensity: 0.0406 Position:1112.4 Intensity: 0.0120 Position: 1128.3 Intensity: 0.0029 Position:1162.3 Intensity: 0.0051 Position: 1192.0 Intensity: 0.0026 Position:1216.2 Intensity: 0.0077 Position: 1256.1 Intensity: 0.0173 Position:1270.0 Intensity: 0.0283 Position: 1292.8 Intensity: 0.0366 Position:1339.6 Intensity: 0.0051 Position: 1357.2 Intensity: 0.0073 Position:1382.1 Intensity: 0.0107 Position: 1389.9 Intensity: 0.0161 Position:1410.2 Intensity: 0.0205 Position: 1431.3 Intensity: 0.0194 Position:1454.8 Intensity: 0.0124 Position: 1476.5 Intensity: 0.0258 Position:1519.9 Intensity: 0.0179 Position: 1580.4 Intensity: 0.0368 Position:1632.2 Intensity: 0.0088 Position: 1651.4 Intensity: 0.00090 Position:1695.3 Intensity: 0.0011 Position: 1717.0 Intensity: 0.00097 Position:2561.9 Intensity: 0.00043 Position: 2835.2 Intensity: 0.0018 Position:2888.8 Intensity: 0.0028 Position: 2937.5 Intensity: 0.0035 Position:2964.4 Intensity: 0.0028 Position: 3062.7 Intensity: 0.0031 Position:3103.4 Intensity: 0.0047 Position: 3197.1 Intensity: 0.0090

FIG. 47 is the RAMAN spectrum of racemic ilaprazole, Form B. Table 23reports the absorbance peaks in the Raman spectrum.

TABLE 23 Peaks in the Raman Spectrum of Racemic Ilaprazole, Form B.Position: 402.3 Intensity: 3.360 Position: 419.7 Intensity: 3.450Position: 437.4 Intensity: 4.555 Position: 469.0 Intensity: 3.223Position: 492.9 Intensity: 2.746 Position: 510.3 Intensity: 3.524Position: 536.4 Intensity: 2.993 Position: 593.1 Intensity: 3.826Position: 612.8 Intensity: 3.449 Position: 623.2 Intensity: 2.192Position: 638.2 Intensity: 1.651 Position: 669.8 Intensity: 2.705Position: 694.0 Intensity: 11.100 Position: 704.1 Intensity: 9.112Position: 732.1 Intensity: 10.557 Position: 754.1 Intensity: 20.453Position: 816.5 Intensity: 9.149 Position: 828.4 Intensity: 4.623Position: 874.1 Intensity: 4.017 Position: 893.0 Intensity: 6.371Position: 954.1 Intensity: 10.071 Position: 969.7 Intensity: 18.993Position: 1015.6 Intensity: 12.072 Position: 1045.9 Intensity: 4.196Position: 1055.6 Intensity: 5.091 Position: 1068.8 Intensity: 6.913Position: 1094.8 Intensity: 9.593 Position: 1110.4 Intensity: 7.641Position: 1128.3 Intensity: 23.427 Position: 1166.2 Intensity: 13.097Position: 1192.1 Intensity: 5.552 Position: 1216.8 Intensity: 15.624Position: 1271.3 Intensity: 59.718 Position: 1292.5 Intensity: 13.415Position: 1306.1 Intensity: 27.370 Position: 1340.8 Intensity: 93.661Position: 1390.2 Intensity: 46.334 Position: 1406.0 Intensity: 24.397Position: 1436.3 Intensity: 30.633 Position: 1460.1 Intensity: 16.408Position: 1482.5 Intensity: 10.635 Position: 1518.8 Intensity: 35.366Position: 1579.7 Intensity: 12.771 Position: 1590.8 Intensity: 17.002Position: 1633.4 Intensity: 34.488 Position: 2737.0 Intensity: 1.265Position: 2835.7 Intensity: 8.761 Position: 2890.1 Intensity: 15.700Position: 2907.8 Intensity: 16.669 Position: 2936.8 Intensity: 15.868Position: 2964.3 Intensity: 6.875 Position: 3006.0 Intensity: 6.752Position: 3019.8 Intensity: 9.329 Position: 3065.1 Intensity: 24.167Position: 3093.7 Intensity: 10.661 Position: 3101.4 Intensity: 11.283Position: 3130.5 Intensity: 15.490

FIG. 48 is the DVS isotherm of racemic ilaprazole, Form B. The DVSisotherm shows a 0.03% weight loss at 5% RH, a 0.04% weight gain from 5to 95% RH, and a 0.00% weight loss from 95 to 5% RH.

Example 6 Ilaprazole Solubility Studies

The solubility of racemic ilaprazole, Forms A, B, and F, were analyzedby exposing them to various ethanol solutions having various pHs for 1hour. Duplicate analysis was performed for each sample on a second day.The solubility in 100% ethanol (with no pH adjustment) is shown in thefirst column. Various other aqueous solutions (87.5%, 75%, 62.5%, and50% ethanol) with varying apparent pHs (7, 8, 9, 10, and 11) were alsoevaluated. All of the values below are the average of two duplicatepreparations analyzed on different days. The results are shown in Table24.

TABLE 24 Solubility of racemic ilaprazole Forms A, B, and F in variousethanol solutions Solubility Ethanol Form (mg/mL) 100% 87.50% 75% 62.5050% A pH 7 6.47 13.13 2.80 pH 8 6.47 15.18 7.18 pH 9 6.47 14.94 3.99 pH10 6.47 18.15 9.48 pH 11 6.47 16.25 6.21 B pH 7 8.38 18.86 3.62 pH 88.38 21.65 9.56 pH 9 8.38 20.61 4.73 pH 10 8.38 24.35 11.86 pH 11 8.3822.34 7.27 F pH 7 7.04 14.82 2.73 pH 8 7.04 17.83 7.43 pH 9 7.04 16.113.54 pH 10 7.04 20.25 9.51 pH 11 7.04 18.01 5.79

The solubility of ilaprazole, Forms A, B, and F, were analyzed byexposing them to 90% ethanol solutions of various pHs for 1 hour. Theanalysis was repeated a second time to check the reproducibility of theresults. The results are shown in Table 25.

TABLE 25 Solubility of racemic ilaprazole, Forms A and F, in various pHenvironments Solubility pH From (mg/mL) 7.0 7.5 8.0 8.5 9.0 9.5 10.010.5 11.0 A Day 1 14.82 15.27 15.51 16.05 16.99 17.66 18.30 18.47 17.63Day 2 15.77 15.45 15.90 16.66 17.66 19.30 19.79 19.85 19.22 Average15.30 45.36 15.71 16.36 17.33 18.48 19.05 19.16 18.43 % Diff. 6.41 1.182.51 3.80 3.94 9.29 8.14 7.47 9.02 B Day 1 19.16 20.37 20.28 20.90 21.7322.79 23.19 23.43 21.59 Day 2 20.91 19.66 20.00 21.56 22.06 24.20 24.1524.66 24.89 Average 20.04 20.02 20.14 21.23 21.90 23.50 23.67 24.0523.24 % Diff. 9.13 3.49 1.38 3.16 1.52 6.19 4.14 5.25 15.28 F Day 116.37 16.89 17.25 17.71 18.32 19.66 20.02 20.28 19.47 Day 2 16.89 16.7516.84 17.66 18.70 20.25 20.66 20.94 20.35 Average 16.63 16.82 17.0517.69 18.51 19.96 20.34 20.61 19.91 % Diff. 3.18 0.83 2.38 0.28 2.073.00 3.20 3.25 4.52

Example 7 Preparation of Characterization of Racemic Ilaprazole, Form E

Approximately 82.0 mg Ilaprazole, Form A was added to a solutioncontaining 6 mL MeOH and 6 μL triethylamine. The solid was dissolvedusing sonication. The solution was filtered through a 0.2 micron nylonfilter into a glass vial. The vial opening was covered with aluminumfoil containing five pinholes and left to evaporate at ambienttemperature. A dark green solid resulted approximately 6 days later andwas identified as Form E.

The XRPD pattern of racemic ilaprazole, Form E was obtained using anInel XRG-3000 diffractometer. The measurement conditions are reported inTable 26. FIG. 49 shows the XRPD pattern for racemic ilaprazole, Form E.Table 27 reports the peaks identified in the XRPD pattern. In its XRPDracemic ilaprazole, Form E may be characterized by peaks at8.1°2θ±0.2°2θ; 10.1°2θ±0.2°2θ; and 12.8°2θ±0.2°2θ. Anothercharacteristic grouping includes the peak at 31.1°2θ±0.2°2θ.

TABLE 26 Measurement Conditions for XRPD Pattern of Racemic Ilaprazole,Form E. Measurement Condition: X-ray tube target = Cu voltage = 40.0(kV) current = 30.0 (mA) Slits divergence slit = 1.00000 (deg) scatterslit = 1.00000 (deg) receiving slit = 0.15000 (mm) Scanning drive axis =2Theta/Theta scan range = 2.519-39.979 scan mode = Continuous Scan scanspeed = 0.0040 (deg/min) sampling pitch = 0.0200 (deg) preset time =300.00 (sec) Data Process Condition: Smoothing [AUTO] smoothing points =57 B.G. Subtraction [AUTO] sampling points = 27 repeat times = 30 Ka1-a2Separate [MANUAL] Ka1 a2 ratio = 50.0 (%) Peak Search [AUTO]differential points = 35 FWHM threshold = 0.050 (deg) intensitythreshold = 30 (par mil) FWHM ratio (n − 1)/n = 2 System ErrorCorrection: [NO] Precise Peak Correction: [NO]

TABLE 27 Peak Positions of Ilaprazole, Form E XRPD Pattern Position (°2θ± 0.20 Relative °2θ) Intensity 8.0 85 10.2 84 12.8 67 14.5 43 16.0 5816.5 88 17.6 73 18.9 48 19.3 70 21.2 49 21.6 46 22.2 57 22.7 100 23.4 4524.7 32 25.8 67 27.2 30 28.7 36 29.2 32 31.3 35 31.9 24 33.7 19 34.7 1835.4 18 37.0 17 38.8 16

FIG. 50 is the TGA thermogram of ilaprazole, Form E. The TG curve showsa negligible weight loss (<0.02%) up to 100° C., indicating the materialis unsolvated. A weight loss of 5.3% is observed from 100 to 170° C.,mostly like due to decomposition.

FIG. 51 is the DSC thermogram of racemic ilaprazole, Form E. Form Eexhibits a minor endotherm near 99° C., and an endotherm near 163° C.(onset: 157° C.) followed immediately by a sharp exotherm. The nature ofthe minor endotherm was not investigated. The remaining DSC events aremost likely due to concomitant melt and decomposition.

FIG. 52 is the ¹H NMR spectra of racemic ilaprazole, Form E, in CD₂Cl₂.Any peaks near 5.32 ppm are due to solvent—not to ilaprazole.

FIG. 53 is the solid state ¹³C CP/MAS NMR spectrum of racemicilaprazole, Form E. The spectrum is externally referenced againstglycine at 176.5 ppm. The peaks positions in the solid state ¹³C NMRspectrum are reported in Table 28, rounded to the nearest 0.1 ppm. Thepeak occurring at 62.4 may overlap with excipient peaks.

TABLE 28 Solid State ¹³C NMR Peaks for Racemic Ilaprazole, Form E. PPMHEIGHT 165.7 85.1 153.2 84.6 148.0 91.7 141.2 99.3 137.7 86.6 135.4 90.9123.9 67.3 122.0 75.8 119.0 95.2 117.0 49.5 116.2 51.5 112.2 66.2 103.664.3 62.4 25.8 56.4 141.8 13.2 74.1

FIG. 54 shows the IR spectrum of racemic ilaprazole, Form E. The IRpeaks are listed in Table 29.

TABLE 29 Peak Positions of Ilaprazole, Form E IR Spectrum. Position(cm⁻¹ ± 4 cm⁻¹) 688 732 756 823 866 890 950 963 1019 1046 1054 1066 10831095 1119 1147 1182 1232 1259 1285 1300 1339 1359 1392 1434 1482 15171525 1585 1629 1733 1905 2363 2594 2800 2840 2889 2980 3008 3068 3128

Example 8 Delayed Release Tablet Formulations

Delayed release tablets containing 40 mg racemic ilaprazole, Form A, B,or F, were prepared and the dissolution rates of the tablets studied.The tablets were identical, with the exception of the crystalline formof ilaprazole. The qualitative and quantitative compositions of racemicilaprazole delayed release tablets, 40 mg (inclusive of the compositionsmade using Forms A, B, and F) are described in Table 30. The delayedrelease tablets, 40 mg, were prepared according to the manufacturingprocess shown in FIG. 55.

TABLE 30 Composition of Delayed Release Tablets, 40 mg QualityIngredient Standard Listed Function mg/tablet Core Tablet RacemicIlaprazole (Form A, B, or F) Internal — Active 40.00 Magnesium HydroxideUSP IID Stabilizer 40.00 Microcrystalline Cellulose (Avicel PH NF IIDDiluent/ 58.75 101) Binder Lactose Monohydrate (Foremost NF IID Diluent58.75 Lactose 312) Microcrystalline Cellulose (Avicel PH NF IID Diluent/58.75 102) Binder Lactose Monohydrate (Foremost Fast- NF IID Diluent58.75 Flo 316) Sodium Starch Glycolate (Explotab) NF IID Disintegrant12.14 Colloidal Silicon Dioxide (Cab-O-Sil NF IID Glidant 0.8983 M5P)Magnesium Stearate NF IID Lubricant 1.980 Subcoat Opadry YS-1-19025-AClear¹ Internal IID Coating 36.67 Material Purified Water* USP N/ASolvent q.s. Enteric Coating Acryl-EZE 93F19255 Clear² Internal —Enteric 36.67 Coating Purified Water* USP N/A Solvent q.s. Total 403.4*Removed during processing. IID - indicates use of the ingredient issupported by FDA Inactive Ingredient Database. q.s.—sufficient quantityN/A—not applicable, solvents are removed during processing. ¹Containshypromellose, USP and polyethylene glycol 400, NF. ²Contains methacrylicacid copolymer type C, NF; polyethylene glycol 8000, NF; sodiumbicarbonate, USP; colloidal anhydrous silica, NF; sodium lauryl sulfate,NF; and talc, USP.

The dissolution rate procedure was modified to be consistent with USP<711>, Delayed Release Method A and to change the UV detectionwavelength in the acid stage of the test. For the acid stage, awavelength of 340 nm was used, and for the buffer stage, a wavelength of306 nm was used. The desired dissolution profile was Q=70% in 60minutes. The dissolution profiles of the tablets containing racemicilaprazole Forms A, B, and F are presented in Table 31.

TABLE 31 Dissolution Comparison of Delayed Release Tablets, 40 mg usingRacemic Ilaprazole, Forms A, B, and F Acid Stage Racemic % DissolvedBuffer Stage Drug Release, % Dissolved Ilaprazole in 2 hrs Average Formin Average Min-Max (% RSD) Tablet Min-Max 15 min 30 min 45 min 60 minForm A 1 54 75 82 86 0-2 48-61 (9.8)  70-78 (4.1) 79-87 (3.6) 84-91(3.3) Form B* 0 34 53 60 65 0-0  1-43 (33.6) 43-59 (8.3) 52-68 (7.5)56-74 (7.4) Form F 0 43 71 83 89 0-0 33-47 (13.0) 66-74 (4.8) 79-87(4.6) 85-95 (5.0) *Stage 1-3 testing conducted per USP. N = 24 resultsreported.

The relatively slower dissolution profile for the Form B tablet wasunexpected based on the relative solubility data for of ilaprazole FormsA, F, and B (A<F<B). The tablets containing Form B drug had a relativelysmaller particle size distribution compared to Form A and Form F. Form Bwas slower to wet and dissolve in the dissolution buffer than Form A andForm F.

Example 9 Bioavailability Study of Ilaprazole from Delayed-ReleaseTablets Containing Racemic Ilaprazole, Forms A, B, or F

The bioavailability of ilaprazole from delayed-release tabletscontaining racemic ilaprazole, Form A, F, and B. This study were toassessed the bioavailability of ilaprazole from ilaprazole 40-mgdelayed-release tablets manufactured as described in Example 8.

Study Design and Dose Administration:

The subjects were randomly assigned in equal numbers to one of threesequence groups (Table 32).

TABLE 32 Regimen Sequences Number of Regimen Sequence Sequence SubjectsPeriod 1 Period 2 Period 3 1 16 Form A Form F Form B 2 16 Form B Form AForm F 3 16 Form F Form B Form A Form A as a single ilaprazole 40-mgdelayed-release tablet. Form B as a single ilaprazole 40-mgdelayed-release tablet. Form F as a single ilaprazole 40-mgdelayed-release tablet. Note: Study drug was administered with 240 mL ofwater following a minimum 10-hour fast. Subjects fasted for 4 hourspost-dose.

Subjects received all regimens in a crossover fashion, according to thesequence group to which they were randomized. For each period,confinement began on Day 1 and ended on Day 2 after all procedures hadbeen completed. There was a washout interval of at least 5 days betweenthe doses of each period. Each subject received 3 doses of racemicilaprazole 40 mg, each dose administered with 240 mL of water. On Day 1of each period, subjects received the regimen to which they had beenassigned at approximately 0800 hours. Subjects were fasted for 10 hoursprior to dosing and remained fasted until 4 hours postdose when astandardized lunch was served.

Sample Collection and Bioanalysis:

Ilaprazole, ilaprazole sulfide and ilaprazole sulfone plasmaconcentrations were determined from 3 mL blood samples collectedstarting on Day 1 at 0 hour (predose), and 0.5, 1, 1.5, 2, 3, 4, 5, 6,8, 10, 12, 14, 16, 20, 24, 28 and 32 hours postdose in each period.Plasma concentrations of ilaprazole were determined using a validatedLC-MS/MS method at PPD (Middleton, Wis.). The lower limit ofquantitation (LLOQ) for ilaprazole and its metabolites was 5.00 ng/mLwith a 0.100 mL aliquot of plasma.

Pharmacokinetic and Statistical Analyses:

Pharmacokinetic parameters for ilaprazole were estimated using standardnoncompartmental methods with WinNonlin Professional Version 4.1(Pharsight Co., Mountain View, Calif.).

Pharmacokinetic endpoints included time to reach the first quantifiableconcentration (t_(lag)), time to reach the peak concentration (t_(max)),the peak plasma concentration (C_(max)), area under the plasmaconcentration versus time curve (AUC) from time zero to the lastquantifiable concentration (AUC_(t)) and to infinity (AUC_(∞)),terminal-phase elimination half-life (t_(1/2z)), apparent oral clearance(CL/F) and apparent volume of distribution (V_(z)/F).

For ilaprazole t_(lag), t_(max), and the natural logarithms of C_(max)and AUCs, an analyses of variance (ANOVA) model was fitted that includedfixed effects of sequence, period, and crystal form as well as a randomeffect of subject nested within sequence. Pairwise comparisons betweenracemic ilaprazole, Forms B or F and Form A, were conducted. Ninetypercent confidence intervals for relative bioavailability betweenregimens were computed.

Pharmacokinetic Results:

Mean concentration vs. time profiles for ilaprazole (linear andlog-linear Formats) following administration of a single 40 mg oral doseof ilaprazole as racemic ilaprazole, Form A, B or F, are presented inFIG. 56.

Mean pharmacokinetic parameter estimates for plasma ilaprazoleconcentrations following administration of a single 40 mg oral dose ofracemic ilaprazole, Form A, B, or F, are presented in Table 33.

TABLE 33 Plasma Pharmacokinetic Parameter Estimates of Ilaprazole inHealthy Adult Subjects Following Administration of a Single 5 mg OralDose of Racemic Ilaprazole, Forms A, B or F t_(lag) t_(max) C_(max)AUC_(t) AUC_(∞) t_(1/2z) CL/F Vz/F (h) (h) (ng/mL) (ng · h/mL) (ng ·h/mL) (h)^(a) (L/h) (L) Form A N 44 44 44 44 44 44 44 44 Mean 1.16 4.14651.68 5066.75 5454.11 8.89 (6.95) 9.34 111.60 CV % 62 24 49 40 38 60 7081 Form B N 44 44 44 44 44 44 44 44 Mean 1.22 3.50 522.51 3812.504087.99 9.48 (7.76) 11.70 160.34 CV % 65 36 38 37 36 63 52 76 Form F N44 44 44 44 44 44 44 44 Mean 1.18 4.01 554.18 4256.66 4672.37 9.66(7.29) 11.29 134.72 CV % 90 26 50 43 40 52 81 54 ^(a)Arithmetic mean(harmonic mean).

Ilaprazole t_(lag) and t_(max) were similar regardless of the crystalform of racemic ilaprazole that was administered. Ilaprazole meant_(lag) averaged about 1.2 hours, and the mean t_(max) ranged from 3.5to 4.1 hours. Ilaprazole mean C_(max) and AUC values were highest forForm A and lowest for Form B. The mean C_(max) and AUC_(∞) values forilaprazole from Form B were approximately 20% and 25% lower,respectively, than those values observed for Form A. The mean C_(max)and AUC_(∞) values for ilaprazole from Form F were approximately 15% and14% lower, respectively, than those values observed for Form A. Theharmonic mean t_(1/2z) values were similar for the Forms A, B, and F,and ranged from approximately 7.0 to 7.8 hours. The mean apparent oralclearance and volume of distribution values were highest for Form B andlowest for Form A. The results of the statistical analysis of the ANOVAare summarized in Table 34.

TABLE 34 Statistical Comparison of Pharmacokinetic Parameter Estimatesfor Racemic Ilaprazole, Forms A, B, and F Parameter Point Estimate 90%Confidence Interval (i) Regimen B vs. Regimen A C_(max) 0.82920.7185-0.9570 AUC_(t) 0.7630 0.6646-0.8759 AUC_(∞) 0.7609 0.6624-0.8740(ii) Regimen C vs. Regimen A C_(max) 0.8456 0.7327-0.9759 AUC_(t) 0.82880.7220-0.9515 AUC_(∞) 0.8456 0.7362-0.9713 Regimen A: Form A as a singleilaprazole 40-mg delayed-release tablet. Regimen B: Form B as a singleilaprazole 40-mg delayed-release tablet. Regimen C: Form F as a singleilaprazole 40-mg delayed-release tablet.

The lower bounds of the 90% confidence intervals for the ratios of thecentral values when racemic ilaprazole was administered as a single oraldose of the 40-mg tablet as Form B (Regimen B), relative to a singleoral dose of the 40-mg tablet as Form A (Regimen A), were below thelower bioequivalence limit of 0.80 for C_(max), AUC, and AUC_(∞), andthe confidence intervals did not include 1. For C_(max) and AUC, thepoint estimate indicated that the values for Form B were approximately17% and 24% lower, respectively, than those observed for Form A.

The lower bounds of the 90% confidence intervals for the ratios of thecentral values when ilaprazole was administered as a single oral dose ofthe 40-mg tablet as Form F (Regimen C), relative to a single oral doseof the 40-mg tablet as Form A (Regimen A), were below the lowerbioequivalence limit of 0.80 for C_(max), AUC, and AUC_(∞), and theconfidence intervals did not include 1. The point estimates indicatedthat ilaprazole C_(max) and AUC values following administration of FormF were approximately 15% and 15-17% lower, respectively, than thoseobserved for Form A.

Pharmacokinetic Summary:

Following administration of a single 40-mg oral dose of ilaprazole asdelayed-release tablets containing Form B, the total systemic exposure,as measured by ilaprazole C_(max) and AUC, was approximately 17% and 24%lower, respectively, relative to a single 40-mg oral dose of ilaprazoleas delayed-release tablets containing Form A.

Following administration of a single 40-mg oral dose of ilaprazole asdelayed-release tablets containing Form F, the total systemic exposure,as measured by ilaprazole C_(max) and AUC, was approximately 15% and15-17% lower, respectively, relative to a single 40-mg oral dose ofilaprazole as delayed-release tablets containing Form A.

Example 10 Solid State ¹³C NMR Study of Racemic Ilaprazole, Forms A, B,F, in 40 mg Extended-Release Formulations

The delayed release tablets containing 40 mg of racemic ilaprazole,Forms A, B, and F, were studied using ¹³C CP/MAS ssNMR. The estimatedlevel of detection for each form as a minor impurity in the major formwas approximately 15% for all three forms. To ensure that approximatelythe same response can be obtained for all three forms and to ensure thatthe observed forms do not have a high or low response, the relaxationdelay and cross-polarization contact times were independently optimizedfor each crystalline form of ilaprazole. All three forms had an optimalrelaxation delay of 10 seconds, and an optimal cross-polarizationcontact time of 4 milliseconds, which conditions were used for thestudy. As shown in FIG. 57, ¹³C CP/MAS ssNMR shows good specificity foreach form. FIG. 57 demonstrates that the regions with the bestspecificity for the three forms do not overlap with the peaks of the 40mg excipient-only placebo blend. The peak positions for each form andplacebo blend are summarized in Table 35. Four characteristic peaks werechosen for each form that are suitable for form identification as a neatAPI and in tableted form and are listed in Table 36.

TABLE 35 Racemic Ilaprazole ¹³C CP/MAS ssNMR Peak Positions forDelayed-Release Formulations Containing Forms A, B, and F and thePlacebo Blend Peak Position (ppm) 40 mg Placebo Form A Form B Form FBlend 165.1 163.5 164.2 179.3 163.9 156.1 152.4 154.7 155 148.4 105.5152.2 148.5 149.5 92.8 145.3 142.2 143.2 89.3 141.8 87.2 139.1 84.0137.2 135.7 137.5 74.7 127.4 72.7 124.1 71.8 122.2 121.5 121.0 69.4120.1 118.3 65.5 116.2 111.8^(a) 110.3^(a) 110.6^(a) 62.0 108.6^(a)107.8^(a) 107.8^(a) 45.5 105.2^(a) 104.5^(a) 37 61.1^(a) 60.4^(a) 33.457.7^(a) 21.8 56.2^(a) 55.7^(a) 56.4^(a) 14.4 12.6 11.5 10.5 ^(a)Peaksthat do not show specificity compared to placebo blend peaks.

TABLE 36 Racemic Ilaprazole ¹³C CP/MAS ssNMR Peak Positions forDelayed-Release Formulations Containing Forms A, B, and F CharacteristicPeak Positions Approximate Peak Positions (ppm) Form A Form B Form F139.1 152.2 156.1 127.4 135.7 143.2 124.1 116.2 110.6 12.6 11.5 10.5

The claimed invention is:
 1. A crystalline form of racemic ilaprazolecharacterized by a solid state ¹³C CP/MAS NMR spectra having peaks at152.2, 135.7, 116.2, and 11.5.
 2. The crystalline form of racemicilaprazole of claim 1, further characterized by on differential scanningcalorimetry thermogram having an onset temperature of about 159° C. 3.The crystalline form of racemic ilaprazole of claim 1, furthercharacterized by a powder x-ray diffraction pattern having peaks at 6.82θ±0.2° 2θ, 9.1 2θ±0.2° 2θ, 22.0 2θ±0.2° 2θ, and 25.5 2θ±0.2° 2θ.